Exploring Indigenous Craft Materials and Sustainable Design—A Case Study Based on Taiwan Kavalan Banana Fibre

Abstract

For a long time, local craft traditions were passed on through apprenticeships. Consequently, new generations of designers and industries cannot easily intervene or produce new designs. This inability to integrate craft traditions in a modern context and changing cultural environment has resulted in the stagnation, decline, or even elimination of such crafts. This study focused on the use of banana fibres in the craft traditions of the Kavalan people of Taiwan, and research-through-design concepts were applied to the creative study of materials that are essential to ecological sustainability and cultural heritage. The method, Material Driven Design (MDD), was implemented through participation to experience traditional processes and explore the visible properties of craft materials. The goal was to gain a holistic understanding of materials and leverage the participants’ expertise in determining which steps in the methods could be improved. This process was supplemented with grounded theory, which was used to analyse and summarise the data in order to understand the factors influencing the creations of participants. Lastly, in addition to producing semifinished and finished products in our experiment, we believe that our findings regarding the examined materials and material tinkering to develop a material-tinkering loop based on the MDD can be (i) combined with the unique insights and technical expertise of designers and (ii) used alongside contemporary technical and digital aids to effectively support the continued development of innovative craft designs.

1. Introduction

In 2019, the Intergovernmental Panel on Climate Change stated that, because of limited resources, climate change, land and ecosystem degradation, and population growth, humans should learn and establish production and consumption patterns that account for the planet’s ecological boundaries to ensure the sustainable use of land resources [1]. Scholars and industry leaders have teamed up to discuss the development of environmentally green and ecological materials and resolve social problems relating to land, food, and energy [2,3]. However, sustainable design is about more than just reducing carbon footprints and using degradable materials; true sustainability also includes the development of a new material culture that emphasises more active engagements, aesthetic significance, and emotional continuance [4]. Consequently, with an emphasis on industrial production and ecological challenges, Taiwan’s government has been promoting circular economy plans, since 2008, in response to the worldwide trend of low-carbon economic development. This also involves advocating for design thinking through the use of local elements in cultural and creative industries, and circular economies that care for the land, to form an emergent consensus with international societies. For example, a Taiwanese innovative design team, Studio Lim, successfully combined traditional lacquering with modern manufacturing by using fibre woodware made from recycled wood shavings and natural flax fibres; the resulting products are lightweight, durable, and softly textured due to the natural fibres. A wide range of natural fibres—including flax, jute, ramie, and banana—are being studied as cost-effective alternatives in the development of composite materials [3,5,6,7]; banana silk is also one such alternative.

The banana is a well-known fruit. From its fruit to its leaves, flower bud, banana steam, and pseudostem, every part of the banana plant can be used. Banana fibres are valued for being lightweight yet stiff and having favourable air permeability and water absorption. In addition, the chemical composition of bananas is rich in cellulose and lignin, but its lower fibre content relative to hemp results in reduced softness, and its high lignin content results in poorer spinnability. Furthermore, the pseudostem of a banana, which is the main agricultural waste that is discarded in banana harvesting, can be effectively used to mass produce banana-fibre products such as banana planks [8,9]. The Swiss backpack brand, QWSTION, sells backpacks made with Bananatex, a waterproof fabric created using 100% natural banana fibres from bananas unique to the Philippines. The Kavalan people of Taiwan, an indigenous tribe based in the eastern region of Hualien County, have preserved their traditional banana-silk weaving techniques, which are registered as an intangible cultural asset by the Taiwanese government because of their cultural uniqueness and ecological sustainability [10]. As the production of ramie threads is seasonal, the Kavalan people switched to banana silk as an alternative material in livelihood crafts for making such items as traditional clothing, backpacks, tote bags, straw capes, straw mats, and decorative screens. Evidently, banana fibre is more than a renewable and self-replenishing resource; it represents an opportunity for people to connect with a meaningful material culture. However, these craft materials and skills are not systematic in terms of design innovation and, consequently, when designers and industries intervene in process development projects relating to craft materials or techniques, they may explore each design projects only through design thinking. Therefore, this study established modern design and innovation values of craftsmanship through the step-by-step completion of a manufacturer process involving materials made from natural banana fibres, including the use of grounded theory to discover, develop, and verify through data collection and analysis.

2. Literature Review

2.1. Value of Indigenous Craftsmanship and Sustainable Designs

Traditional crafts are mostly made from natural materials and reliant on artificial processing and the use of ecological resources. In recent years, challenges relating to the transfer of the world’s intangible cultural heritages [11], the role of creative industries, ecological and sustainable management, and the representation of local culture have shone a spotlight on the craft industry and craftspeople. To address challenges related to sustainable design, traditional crafts also incorporate values that are linked to the regional context, cultural knowledge, and practices [12,13,14].

Crafts are environmentally friendly because they emphasise hand processing and the use of natural and renewable materials such as wood, wool, and plant dyes. In the context of the local use of natural materials by the craft industry, these materials determine the longevity of economic sources for stakeholders; consequently, the renewability of materials has received increasing attention [15,16]. The social anthropologist Michael Howes stated that the knowledge base and practices of indigenous peoples can often be utilised to emphasise the sustainability of the environment and human communities, especially in localised ecosystems [17]. Howes argued that this knowledge must be explored and applied in the development of modern science and technology. Benyus contended that most indigenous peoples abide by the ecological laws of nature and formulate, on the basis of respect for nature, codes of conduct that apply to hunting, gathering, and fishing. Hunting animals needlessly or wasting any part of an animal are considered taboo behaviours [18]. According to Polanyi (1997), craft knowledge is transferred as tacit knowledge, which is typically described as the concept of “we can know more than we can tell” [19]. This also indicates that crafting is the formation of tacit knowledge through the physical movements and practices of craftspeople [20]. Tacit knowledge is also defined as a type of bodily kinaesthetic intelligence in which the connection between perception and conceptual thinking is limited [21,22]. By contrast, Adamson argued that a craft is, by definition, a practice and also a method of thinking that is realised through various practices; this method of thinking can be broken down into category, object, idea, and process [23]. Each category of craft (such as pottery, woodworking, and lacquering) has its own material knowledge, techniques, and processes and influences the thoughts of creators and the execution of object creation through various cultural symbolisms, implications, and emotions [24,25]. Adamson further defined craft as the act of “making something well through hand skill” [23], emphasising the role of hand skill in craftwork. The consumer market’s increasing rejection of innovations led solely by technology highlights the key role of crafts in the development of innovative products. The emphasis on visual, tactile, and emotional qualities can be attributed to the creativity inspired by the crafting process, the ability to convey meaning through form, and the sensitivity of people to materials [20,22]. Therefore, by presenting the value of hand skills in craft, a greater emphasis is placed on discussing the nature and manufacturing process of craft materials and the process of forming objections.

2.2. Material Designs in Material Driven Design

Karana et al. (2015) published “Material Driven Design (MDD): A Method to Design for Material Experiences” to establish a record of designers’ designs and experiences with materials at hand and understand how a material behaves under different circumstances or reacts to different techniques or manufacturing processes, the interpretation of materials, and design behaviours driven by materials, with the purpose of guiding the development of materials [26]. The MDD method emphasises the designer’s process, which moves from the tangible to the abstract and then back to the tangible, in addition to the journey of a material from the final design stage back to hands-on experimentations, material priming, and prototyping [27]. The method comprises the four following steps: (1) understanding the material (i.e., technical and experimental characterisation); (2) creating a visual experience of the materials; (3) manifesting material experience patterns; and (4) designing material/product concepts. The MDD method also emphasises how the potential properties of a material can guide specific forms of manipulation [28], such as material tinkering, participants documenting the material-making process to build knowledge on material tinkering, and collaborations between material stakeholders [23,26,29,30,31,32]. By reviewing their understanding of the continuity among the design, timing of use, and structure of the materials, researchers can introduce new steps or a material taxonomy to analyse material growth environments, compositions, processing, and structures and thereby produce new findings related to the role of materials and the experiences of users. Consequently, the MDD method allows for the development of derivative forms, functions, and experiences of materials that are not yet fully developed [33]. Relevant examples include materials made from recycled waste (e.g., mussel shells) [34], 3D textiles and printing [35], organic biomass materials (fungus filament) [36,37], smart materials that require further development [38], and the development of artificial textiles made from plant roots [39].

The Kavalan people of Taiwan have been weaving and crafting with banana fibres for more than a century [40]. The MDD step of understanding material characterisation stresses developing an understanding of raw-material collection, especially regarding the acquisition techniques used in traditional crafting and the historical and cultural knowledge of materials. Meanwhile, how these materials interact with users under various conditions (e.g., compression or varying temperatures), what issues arise related to these materials (from a human perspective), and how people respond to these materials [28] are also significant. Moreover, by studying the continuous relationship between innovation and inheritance, anthropologists can examine the cultural information pertaining to the creation, use, or transformation of objects by humans within the context of material culture; this includes the conversion of raw materials into products, artefacts, and objects and its implications for the evolution of life [41,42]. Ingole’s proposal of different materials and material variability is illustrated in Figure 1. The connection between objects and human life can be envisioned as two lines flowing in parallel; specifically, one line represents the flow of consciousness in the form of life, sound, and sensations, whereas the other line represents the flow of materials that circulate, mix, and merge. Along the two vertical flow paths, two horizontally aligned nodes—image and object—are generated [43].

That is, in the flow of consciousness, the cultural connotations of a craft that are conveyed through objects are regarded as characteristic representations of a tribe’s craftwork, and the emphasis on cultural values in design is naturally regarded as a key aspect of the design process [44,45,46]. In particular, in the strategic model of culture as product design, Lin specifically targets the four main steps proposed for extracting and transforming Taiwan’s indigenous cultures in product design: investigation (i.e., set a scenario), interaction (i.e., tell a story), development (i.e., write a script), and implementation (i.e., design a product) [47].

Instead of attempting to understand the meaning and image transformation of various cultural characteristics in the flow of consciousness with respect to communication, the present study emphasises the flow of material by focusing on the MDD strategy of encouraging designers to understand the essence of tribal craft materials. This includes considering the physical properties of the material, historical background of a craft, and material weakness tinkering. These relationships drive designers to identify new ways of applying a material through scientific experiments [48]. MDD plays a key role in this process by initiating a new step in design evolution with each turn.

2.3. In-Depth Analysis of Grounded Theory and Practical Significance of the Research-Through-Design Method

Grounded theory is a contextual examination that provides researchers with a method for systematically describing the qualitative details of a phenomenon that is being studied [49]. It is used to reveal the connotations of people’s experiences and to explain little-known phenomena that exist under the surface. Qualitative social-research methods are used to establish the sustainable and systematic design logic developed by designers for indigenous craft materials. Turner argued that grounded theory is particularly applicable to qualitative data, such as of participant observations, face-to-face interactive observations, semi-structured or unstructured interviews, case studies, and documentation [50,51]. Consequently, in the present study, grounded theory was used for the case studies, interviews, experience logs, and literature review at this stage (e.g., discussions of qualitative data such as the written descriptions provided by the study stakeholders and the study participants during the trial process) to inform the design practices for the next stage of the present study. According to Strauss and Corbin, grounded theory involves the collection of data within the scope of a study and subsequent analysis of the data in accordance with specific standards (e.g., systematic comparison of data texts) [51,52]. As such, the collected data were consistent with the structures of the sensitive and key questions that are highly relevant to the present study. The back-and-forth process of text-data analysis enabled researchers to repeatedly review each step, which facilitated subsequent research observations and the integration of questions and results. The data analysis results were then categorised in rational and structured tables to determine the behavioural and textual correlations between workshop participants, stakeholders in banana-fibre crafting, and documents on Kavalan crafts. Lastly, the data analysis and property results were used to develop a craft innovation model for banana-fibre materials used in design research. In the present study, from the analysis of banana-fibre materials to the application of design concepts, the presentation of design-entity concepts gradually took shape during a series of repeated design trials that were conducted by the designer. The aforementioned process describes the concept of research through design (RtD), which is realised in the field where design work is actually conducted [53]. RtD is a design method that is established through the design process, and it involves the documentation and communication of key actions such as material research, development work, experimentation, and design repetition [53]. RtD is also used by researchers as a research method for resolving various problems (incompleteness, contradictions, and changes) [54,55] and for understanding the broader design context.

Notably, RtD has two main mechanisms. The first is the defence of research specificity [56,57,58,59]; as described by Frayling, RtD treats design as a unique form of thinking and a unique method for establishing knowledge that can further our understanding of non-design topics. The second is the foundation of design research based on existing academic research precedents or methods, particularly in the context of natural sciences, social sciences, and the arts [53,60,61]. Gaver and Bowers proposed that the similarities and familial resemblances of artefacts manifested through design research can be summarised using annotated portfolios, which combine visual information with concise descriptions. The resultant intermediate knowledge enables designers to express the indexical connections of their design as research design and communication, providing them with an alternative means of interpreting and predicting the composition of a design in research outcomes [62,63]. In essence, annotated portfolios present specific design objects and provide corresponding textual descriptions; compared with the application of unsuitable scientific research methods, the intuitive explanation of evidence associated with annotated portfolios is a more appropriate method for verifying design in research [62]. Consequently, when we return to the material as a starting point in MDD to examine how the essence of materials and their samples inspire design concepts (for the purpose of highlighting the application value of crafting), we must exploit the objectives of RtD [63] to systematically examine the concepts pertaining to material sampling, material tinkering, and prototyping, and gradually adjust the designs in our study. Furthermore, the annotated portfolios were empirical designs for validating MDD practices in design research [59,60]. Lastly, the experimental product designs were completed with the application of RtD concepts and subsequently used to establish a guiding method for designers [64,65].

3. Methodology Framework

The present study took the form of community- and regionally specific craft cultivation programs that were launched by the National Taiwan Craft Research and Development Institute (NTCRI) in 2018, and it was expanded to include a craft-material-making program that was launched in 2021. The goal of these programs was to establish the sustainability of Taiwan’s local craft industry by preserving and promoting Taiwan’s craft culture and by helping communities to build a consensus on the development of craft communities.

The present study was conducted in three phases (Figure 2). The first phase involved the holistic exploration and understanding of the material significance of traditional Kavalan banana-fibre crafts through an MDD design workshop. Semifinished products, which were produced through the innovative use of materials by designers and craftspeople, were used to restructure visible knowledge and construct a design foundation (Phase I). In the second phase, an in-depth content analysis was conducted in accordance with grounded theory [51], whereby local banana-fibre craftspeople (i.e., stakeholders) were interviewed to obtain an understanding of the management and development of banana-fibre crafts and the current status of actual traditional materials and techniques, and the engagement of the study participants in the exploration, tinkering, and repeated deconstruction of banana fibres during workshops was recorded. The purpose was to determine the invisible power that drives material expressions and innovative designs during exploration of the material (Phase II). Lastly, to support the results from the analysis in Phase II and to establish MDD commodification design practices, Phase III was conducted by inviting two research students specialising in product design who were undergoing received professional design training (i.e., they have product development skills that have not yet been rigidified by industry experience) to interact with the three craftspeople who demonstrated high degrees of concrete realisation during the Phase I prototyping process. The main activities were as follows.

4. MDD-Based Design Intervention for Banana-Fibre Craft

For Study 1, which was carried out during the workshop conducted in Phase I, the MDD method was used to apply material design and analysis methods as part of continuous research on craft-material design information. The study comprised 20 participants (i.e., nine craftspeople including potters, weavers, and woodworkers; nine designers, including industrial designers and visual communication designers; and two non-Taiwanese industrial-design student interns). Under the guidance of two MDD experts, who were invited by the National Taiwan Craft Research and Development Institute Taipei Branch (NCTRI) to participate in the present study, the aforementioned participants participated in an eight-day participatory design workshop and conducted design concept prototyping for 1 month in accordance with the procedures for traditional Kavalan banana-fibre crafting (from material collection to design-prototype concept output). MDD integrates the concept of material-culture evolution into the design intervention principles for banana-fibre crafting; the designer plays the role of an archaeologist or anthropologist who, during the design–practice loop of material tinkering, forms the meaning of material tinkering and traces of a concept prototype or cultural information by reviewing the past and building a new material vision. Emphasis is placed on the appearance of the material prior to tinkering and the evolution of this appearance in each loop.

The banana-fibre material-preparation procedures (Figure 3), which were based on crucial information and indices in each action step of the actual operations that were implemented during the workshop, were investigated in the present study. The procedures of Phase I of the present study emphasised the translation of craft into design–concept–practice. Action Step 1 (i.e., understanding the material) pertains to the culture and background of traditional tribal banana-fibre crafting; this involved observing the material’s properties and qualities and understanding both traditional and other feasible material-processing techniques (illustrated in Section 4.1). Action Step 2 (i.e., material vision) was performed on the basis of material-tinkering-related experimental information that was obtained through material analysis and the material embodiment by the users of craft manufacturing techniques (illustrated in Section 4.2). In Action Step 3, basic sensory information of the users (in relation to the material) was collected (illustrated in Section 4.3). In Action Step 4, the emphasis was on forming a loop for the process of design–concept–practice by applying the MDD-based action of material tinkering (Action Step 1); the participants introduced information related to their material experience journey into the loop, and they repeated operations and examinations through material tinkering and experimented with processing techniques and trial design prototyping, thereby echoing the design concept that was formed during the material-tinkering process (illustrated in Section 4.4).

4.1. Action Step 1: Material Understanding

Three days before the workshop was conducted during Phase I, the 20 participants and the two MDD experts visited the source of the banana-fibre material that was examined in the present study (i.e., Kavalan Xinshe Village in Hualien, Taiwan) to conduct a field study on this material (Figure 4). During this activity, the participants were asked to collect banana fibres in person. In addition, village elders and tribespeople provided guidance on traditional craftmanship, and the participants gained a deeper understanding of the history and culture of the banana-fibre material through their dialogue with the MDD instructors [26]. Subsequently, the traditional process of banana-fibre-material making was illustrated, as shown in Figure 5, by organising the activity outcomes.

The processing and manufacturing (e.g., bending, forging, gluing, and cutting) of the material affects its performance in terms of its structure (including the microscopic molecular composition and the macroscopic visual structure) and properties (e.g., hardness and strength, which includes compressive strength and shear resistance). Accordingly, the concept of material connections classification in crafting is similar to that in materials-science technology and research. Therefore, after the participants understood the traditional manufacturing process of the material examined in the present study, they summarised its properties, preparation process, visual structure, and the growing environment by following the MDD method and preparing a material taxonomy prior to the material-tinkering activity (Figure 6); the material taxonomy served as a reference for clarifying the subsequent MDD-based material tinkering. The material taxonomy comprised four primary components, as follows: (1) material ingredients refer to the compositional quality of banana-fibre material (including its organic natural fibre, recyclability, degradability, natural smell, and biological water resistance); (2) growing conditions refer to the growth-related environmental factors to which bananas are exposed (e.g., cultivation near a harsh seashore environment, lack of fertilisation, and insect bites); (3) material structure refers to the dimensions of material composition (including two- and three-dimensional configurations and composition heterogeneity (density and stratification)); (4) material treatment refers to material processing (including post-processing steps such as dyeing, pressing, hot pressing, and drying). The four aforementioned aspects influence one another. For example, variations in dyeing can develop because of differences between growing environments. Therefore, controlling for variations relating to coefficients or correlational factors can be highly challenging.

4.2. Action Step 2: Material Vision

Building a material usage vision involves helping the participants to extract the correlation and consistency in their understanding of the banana-fibre material. This step aimed to guide each participant to reflect on correlational connections and key issues, thereby enabling them to define a key and unique vision about the banana-fibre material on the basis of their exploration. For example, the participant DF with a background in industrial-design training was intrigued by the action of “chewing” the material. The participant felt that the act of combining added materials led to interactions with other daily necessities and that repair and collage were ideal methods for expressing conflicting beauty. With respect to this topic, the participant said the following:

In learning to extract banana fibre as a material, I observed, through the community craftsmen’s demonstration, how they retained the fibre that is suitable for weaving. The fibre did not possess the quality of a twist thread for weaving because of its inferior strength due to insufficient growth. Consequently, the core material and the split that remained after the fibre was drawn were generally used to make fertilisers (natural agricultural waste) or soy sauce. The natural structural texture of the banana’s core material, the split that remains after the fibre was extracted (the banana plant has no trunk because it is not a tree; the appropriate term is pseudostem; the structure that supports the pseudostem is referred to here), and the combination of its edibility (chewing) with the fibre residues from chewing (natural organic matter) inspired me to think of the material as something that can be “broken down and used for repairs”. Therefore, I designed a banana fibre–based repair glue to incite users to reflect on object regeneration on the basis of reusing the fibre.

(Quoting from participant’s words)

4.3. Action Step 3: Material Pattern

After the steps of material understanding and preliminary material-tinkering categorisation were completed, the MDD experts introduced tools for the experiential characterisation of materials; specifically, tools for material-driven material selection (MDMS) [66] were used to collect quantitative data comprising four levels of experiential feedback, namely, sensorial, interpretive, affective, and performative feedback. Thus, the users conducted a material perception evaluation on the basis of relativity (e.g., qualities of smoothness and roughness) within the frame of five designated scales of values. For example, Figure 7 presents the MDD tool kit for the sensorial level in the experiential characterisation of the materials examined in the present study. The material perception evaluation was conducted through interviews with the participants to understand their perceptions and feelings regarding the banana-fibre material (including their visual, tactile, and emotional perception).

4.4. Action Step 4: Material-Tinkering Loop

Action Step 4 of the MDD method is regarded as a recyclable loop. Specifically, the material tinkering performed in Action Step 1 served as the loop in the design prototyping practice and experimental flow in Action Step 4, and it gradually formed a systematic structure involving design thinking for design practice cases through continual experimentation, manufacturing, and modification processes involving the sample material. The role of participants in material tinkering is that of a chef; they have to evaluate the materials that are available and consider their options for cooking the “ingredients” that they have, which vary depending on their familiarity with the materials and tools or their individual specialty. Experimental material tinkering was the starting point for entering the loop. Due to the large sample size of the present study, only specific representative samples are presented. The experimental case samples are presented in Figure 8. CH, a participant who specialises in fibre crafts, experimented on basic food-processing techniques for treating composite materials, which included candying, salting, and caramelisation. Figure 8a shows the candied and heated caramelised samples. The material thinking of DD, a participant who was an industrial designer, accentuates the functional aspect through reinforcing of the fibre structure with metallic fibre (Figure 8b). CF, a participant who was a woodworker, experimented with pulp blending and the addition of natural resin glue by applying the concepts of material compounding, water absorption, and for maintenance of the material’s natural grid structure (Figure 8c,d). After presenting their sample materials through preliminary experimental tinkering, all the participants were guided on the operation of material re-tinkering by the experts.

The observations and summary at this phase revealed that, because the material used in the present experiment was drawn from the banana stem (the form of which is a complete plant stem), the participants generally focused on deconstructing and recombining banana fibre using the following techniques: (1) adding—beeswax, gelatine, white glue, epoxy resin, pulp, clay, and metallic fibre were added to endow banana fibre with water resistance and to reinforce its structuredness; (2) drying—hot pressing, baking, or natural sun-drying were performed to reinforce the fibre structure and enhance its resilience; (3) smashing—aggressive and comprehensive damage was dealt to the banana-fibre material through the use of choppers or high-speed mixers, and the material is then blended with heterogenous materials for recombination and formation, thereby expanding the plastic-related applications of the product.

Material-tinkering development varied among participants. To allow the participants to appreciate each other’s works and engage in mutual exchange, an evaluation of semi-developed material was conducted for the fully tinkered sample materials in the form of periodic presentations (Figure 9 and Figure 10). The two MDD experts—a senior NTCRI researcher and the first author of the present study—also participated in the evaluation and provided the participants with suggestions and feedback before vision-based design prototyping was performed; this encouraged them to reflect on the breakthroughs that were achieved in terms of design concept and prototype development [67].

Finally, the 19 design concept prototypes that were completed in this phase were preliminarily divided into three categories, namely, lampshades (six pieces), daily necessities (five pieces), and accessories and artistic creations (eight pieces). On the basis of the taxonomy and the three categories of material-tinkering techniques, six cases of work were selected and presented (

Table 1. Six cases of work selected during Phase I (Appendix A presents a comparison table of participant codes, and Appendix B provides a summary of the 19 works).

Category of Design Concept	Code	Sample Material	Design Prototype Development Brief	Material-Tinkering Techniques
Lampshade	DA		The possibility of 3D banana-fibre formation: designer Kuan-Cheng Chen made use of the shrink ability of dried-banana thread fibre and fitted banana threads into moulds for sun drying/baking, thereby allowing the fibres to be shaped in accordance with the shapes of the moulds.	Moulding and drying
	CF		Use of discarded banana stems: woodworker Jing-Teng Lin began by thinking about bark from which no thread could be drawn. Lin then re-deconstructed various banana-tree compositions (including waste banana skin and discarded structures that were not used to draw threads), which were subsequently used to develop fibre paper.	Smashing and adding (pulp)
Daily necessities	DF		Natural fibre: by compounding composite materials, designer Chung-Han Lu developed material applications based on the concept of repair.	Smashing and adding (paste and agar)
	CB		Banana-silk fibre and soap: craftsperson Ching-Yi Chou sun-dried the thick fibre in a banana stem and used it to produce cleaning tools or added it into handmade soap. The tissue of used fibre can be reused, and it degrades naturally.	Drying and adding (handmade soap liquid)
Accessories and artistic creations	DD		Banana-silk soft plastic lampshade: designer Benson Liu sliced away entire banana-leaf sheaths and removed the outer skin, retained the grid structure at the centre of the banana stem, and then performed interlaced weaving with metallic fibres.	Drying and adding (composite weaving)
	DI		Land and roots: designer Ching-En Yeh utilised the materials and method of pottery firing and fired banana threads combined with Taiwanese endemic materials into bricks.	Adding (black soil and sand) and firing

). The material-tinkering techniques included: material shaping and drying using moulds; an orientation towards the concept of fibre paper making was realised by smashing the material and experimenting with the addition of pulp, paste, and agar to allow for the broken starchy material to be shaped through gluing during the drying process; reinforcing the material structure by weaving metallic fibres into the grid interstices of the banana fibres; adding fibre to handmade soap to create bath balls as an alternative product; adding fibre to clay by applying concepts such as pottery firing.

5. Grounded Theory Analysis

5.1. Evaluation Standard and Method

The grounded literature review was based on two studies that examined the banana-fibre weaving techniques of the Kavalan tribe [68,69], and interviews were held with the advocates of banana-fibre weaving techniques of the Kavalan tribe community in Xinshe Village, Hualien (i.e., Ching-Ying Pan, the leader of the local banana-fibre-weaving workshop in the Kavalan community, and Shu-Yen Chen, a banana-fibre weaver who resides in the community). Qualitative grounded-theory coding was subsequently performed by referencing the narratives of the 20 participants of the banana-fibre workshop with respect to their personal self-observations and recorded operational behaviours. The grounded analysis aimed to summarise and validate sections in the literature detailing the experiences of the participants from the procedures of material analysis to the formation of design imagery and the establishment of the Kavalan community’s expectations regarding banana-fibre crafting. The results serve as a reference and established prior knowledge for Phase III of the present study, that is, the design implementation phase. Grounded content was jointly analysed by the first author of the present study and two NTCRI researchers; one researcher had a background in weaving crafts, and the other was a researcher of this research project. The qualitative-research software Nvivo12 was used to compile the data obtained from Study 1, which included information on the history, culture, materials, and craft techniques pertaining to the workshop and its evolution.

5.2. Coding Results

A considerable amount of data on banana fibre was collected from online articles, design cases, and videos, and they overlapped with the recorded interview content; hence, only a part of the data was used for the grounded-theory analysis. Therefore, the present study only performed grounded coding using data that contained research evidence (

Table 2. Axial-coding results based on the relevant literature, interviews, and records of participant experiences.

Axial Code	Open Code	Node Amount	Example of Open Code
Problems and recognition	(1) Problems encountered in the development of traditional techniques	16	Example of Open Code (1) Simplifying procedures while obtaining the largest pieces of the material is crucial to the material selection process.
	(2) Recognition of innovative development	10
2. Value of banana fibre	(3) Value of indigenous traditions	18	Example of Open Code (5) Banana fibre is an essential weaving material for clothing and daily necessities in the Kavalan community. The material is sourced from an indigenous species; it is a native, natural, environmentally friendly, local, and traditional material for the community.
	(4) Cultural continuity and inheritance	31
	(5) Naturalness and environmental friendliness	43
3. Essence of banana-fibre material	(6) External (intuitive) image	11	Example of Open Code (8) The material is a smooth, flaky fibre with low cohesion (i.e., degree to which the fibre can be twisted and stuck together).
	(7) Material physical structure	9
	(8) Performance of physical properties	11
	(9) Similarities with other materials	2
4. Lifestyle applications	(10) Textile and processed lifestyle products	11	Example of Open Code (10) In Kavalan tradition, banana fibre is woven into straw mats, nets, coats, and belts that are worn with their traditional hemp clothing.
	(11) Dietary consumption	5
5. Development of new design thinking	(12) User-oriented design	4	Example of Open Code (13) Traditionally, the discarded section of the banana split, specifically the stem, is used as a crucial material for non-weaving purposes.
	(13) Material-processing–oriented design	85
	(14) Creative attempts to use physical properties of material	39
	(15) Innovative applications for composite materials	70
Total 5	15	365

). In total, 365 nodes, 15 open codes, and five axial codes were compiled, and the five axial codes were as follows: (1) problems and recognition, (2) value of banana fibre, (3) essence of banana-fibre material, (4) lifestyle applications, and (5) development of new design thinking (Table 2 and

Table 3. Analysis of node distribution in each axial code.

Axial Code	Research Participants (Craftspeople)	Research Participants (Designer)	Stakeholder Interview	Literature Data	Total Percentage
1. Problems and recognition	5.38%	2.82%	14.29%	33.33%	7.31%
2. Value of banana fibre	22.31%	14.79%	67.35%	23.81%	25.73%
3. Essence of banana-fibre material	5.38%	16.2%	2.04%	9.52%	9.65%
4. Lifestyle applications	6.92%	3.52%	2.04%	4.76%	4.68%
5. Development of new design thinking	60%	62.68%	14.29%	28.57%	52.63%
Total	100%	100%	100%	100%	100%

). Subsequently, selective coding was performed for the axial code for which the largest number of coding results was obtained (i.e., new design thinking) and the axial code of interest to the present study (i.e., value of banana fibre). The output tree nodes for the axial code “new design thinking” were (1) user-oriented design, (2) material-processing-oriented design, (3) creative attempts to utilise the physical properties of the material, and (4) innovative applications for composite materials. For the axial code “value of banana fibre”, the output tree nodes were (1) value of indigenous traditions, (2) cultural continuity and inheritance, and (3) naturalness and environmental friendliness.

Table 4. Analysis of node distribution in open codes for “development of new design thinking”.

Open Codes	Research Participants (Craftspeople)	Research Participants (Designer)	Stakeholder Interview	Literature Data	Total Percentage
(1) User-oriented design	1.22%	3.16%	0%	0%	2.09%
(2) Material-processing-oriented design	43.9%	44.21%	57.14%	14.29%	43.46%
(3) Creative attempts to use physical properties of material	17.07%	18.95%	28.57%	14.29%	18.32%
(4) Innovative applications for composite materials	37.8%	33.68%	14.29%	71.43%	36.13%
Total	100%	100%	100%	100%	100%

and

Table 5. Analysis of node distribution in open codes for “value of banana fibre”.

Open Code	Research Participants (Craftspeople)	Research Participants (Designer)	Stakeholder Interview	Literature Data	Total Percentage
(1) Value of indigenous traditions	9.28%	9.09%	36.36%	20%	19.57%
(2) Cultural continuity and inheritance	12.5%	27.27%	54.55%	60%	33.7%
(3) Naturalness and environmental friendliness	78.12%	63.64%	9.09%	20%	48.74%
Total	100%	100%	100%	100%	100%

present a further analysis of the aforementioned tree nodes.

5.3. Key Point Analysis

Table 3 presents the preliminary analysis results of the collected raw data through the use of axial coding. The columns compare the density levels of the nodes in the coded data. Among the participants in Phase I of the workshop, both craftspeople (60%) and designers (62.68%) expressed a considerable level of concern over the development of new design thinking. Additionally, the total percentage statistics also suggest that the axial code “development of new design thinking” was considered more important than the other axial codes (52.63%). The statistics also reveal that the local banana-fibre craftspeople (i.e., stakeholders) are highly concerned about the value of banana fibre (67.35%); the percentage of nodes that represented the “value of banana fibre” axial code (25.73%) in the interview record was less than only the percentage of nodes that represented the “development of new design thinking” axial code.

Accordingly, the axial codes “development of new design thinking” and “value of banana fibre” were adopted for selective coding. Table 4 and Table 5 present the open coding-analysis results. The density of the nodes that represent “material-processing-oriented thinking” and “innovative applications for composite materials” among the responses of the craftspeople and designers were comparable. Additionally, craftspeople and designers were more concerned about “material-processing-oriented thinking” than “innovative applications for composite materials” (craftspeople, 43.9% > 37.8%; designers, 44.21% > 33.68%). The density of the nodes that represent “material-processing-oriented thinking” (43.46%) was also greater than those representing “innovative applications for composite materials” (36.13%). This indicates the crucial role of the individuals with “material-processing-oriented thinking” (both designers and craftspeople) in product manufacturing or design. Furthermore, the density levels of the axial nodes in the stakeholder interview and literature data were notably high or low. For example, 0% of the interview records and literature data consist of nodes associated with “user-oriented design”. The interviewees received professional training, which centred on the inheritance and presentation of weaving skills, but their interviews did not reveal any narratives associated with “user-oriented design”. Similarly, the literature data detailed the contextual background of Kavalan culture, knowledge on the banana-fibre-weaving craft, and the innovative development of cultural industries, but they did not cover “user-oriented design”. Therefore, the density of the nodes in the interview records suggest a high degree of concern about “material-processing-oriented design” (57.14%); the density of the nodes in the literature data were concentrated around the theme of “innovative applications for composite materials”; this is because the literature data has explored industrial innovations for developing crafting culture (71.43%).

To explore how banana fibre is used as a crafting material by indigenous people, the present study used selective coding to analyse the density of nodes representing the “value of banana fibre” (Table 5). According to the statistics, the nodes were clustered in two regions. Craftspeople (78.12%) and designers (62.64%) examined in the present study regarded the “value of banana fibre” code to be within the “naturalness and environmental friendliness” dimension; by contrast, the participants from the interview records (54.55%) and literature data (60%) expressed a high degree of concern about the cultural continuity and inheritance dimension.

6. Applying Material Exploration Samples in Design Implementation

The present study proposed a design template to devise applications for banana fibre within a three-month period. The template expands upon the concept model in Phase I and the grounded-analysis results obtained during Phase II. Three participants from Phase I (i.e., two designers and one craftsman) were invited to evaluate the practical extensiveness and feasibility of the devised design practice; they were invited because of their willingness to continue participating in the present study. As a designer, Kuan-Cheng Chen has long-accumulated interdisciplinary development experience in the crafts and design industry. Chen’s contributions to and participation in the design process provided a meaningful reference for the present study. The other designer, Chung-Han Lu, has continually participated in the present research project (i.e., self-manufactured crafting material project) and has extensive experience in applying MDD in material exploration. The two designers referenced the material-tinkering method used in Phase I (i.e., use of shredded materials), which was similar to the method applied by the woodworker Jing-Teng Lin. Additionally, to overcome the limitations of traditional crafting techniques and design-thinking frameworks, the present study recruited a student (coded as “SA”) from a master’s design program to apply her basic design training and basic research literacy. The participation of SA served to provide the perspective of an individual whose design thinking has yet to stagnate during the design-implementation process.

In this phase, the researcher guided the participants in reviewing key points of the literature on MDD, and they gave each of the participants, as a reference, a copy of The New Fiber World-Taiwan Local Material Exploration and Creative Experience, a book in which the results of Phase I (i.e., workshop) were published [70]. Additionally, prior knowledge that was constructed based on grounded-theory analysis was provided to the participants to increase their support of the use of banana-fibre materials. The results observed in Phase I indicate that the participants were generally interested in reusing the discarded banana stem after fibre extraction. The interest of the participants was particularly apparent when they were discussing the possibilities of innovating traditional crafting techniques. Notably, the participants maintained that, because the banana fibre is an all-natural material, the opportunities to reuse waste materials resulting from traditional crafting methods are particularly meaningful. Furthermore, the results of the grounded-theory analysis in Phase II indicated that the open code “material-processing-oriented thinking” of the axial code “development of new design thinking” was highly focused on the literature data. These results reveal that the vision of the participants regarding the development of banana-fibre materials was mainly focused on how they could further process usable materials and how they could apply material tinkering to overcome the difficulties encountered during the commercialisation of products made using the banana-fibre material. Accordingly, the time allocated for the participants to understand the basic characteristics of banana-fibre materials was reduced, thereby enabling the participants to quickly and systematically shift their focus to the material-tinkering loop.

6.1. Design Implementation of Material Exploration

In this phase, the evolution of the design process of three experimental cases was explored.

6.1.1. Case 1: Using Drying Shrinkage Characteristics of Banana Fibre for Design Shaping

This experiment was performed by the designer Kuan-Cheng Chen, who participated in Phase I of the present study, during which the drying shrinkage characteristics of banana fibre were explored. Banana fibre was fit into a mould and subjected to sun-drying or baking to form the desired shape (Figure 11). During this phase, the shapes and design of the material and mould can be further adjusted.

Due to the designer’s concept product in Phase I was similar to the shape of the complete product, the design vision of the new material had been successfully extended in Phase I. Additionally, on the basis of previous experience, the focus of material tinkering was placed on overcoming the dependence of dry material on the mould. By adjusting the mould processing process and referencing how the previous participant of the experiment (coded as “CE”) applied fibre weaving in material tinkering (Figure 12), the designer adjusted the design concept model that was established during this phase (Figure 13). (courtesy of NCTRI)

The design that was developed in this case is relatively conservative compared with that of the other two experimental cases. The application of composite material in weaving has been explored in the modern field of crafting. For example, for the 2011 Taiwan–France Hand in Hand project launched by the NCTRI, designer Patricio Sarmiento used a composite material consisting of bamboo strips and leather to create a novel bamboo-weaving craft design (Figure 14). The use of banana stem in this design emphasised the light transmittance of the material. Furthermore, Sarmiento’s professional background in digital design enabled him to adopt parameter design to create a framework for the lamp to transcend the limitations of traditional weaving crafts.

6.1.2. Case 2: Applying Material Shredding and Mixing in the Design of Disposable Tableware

In Phase I, the designer Chung-Han Lu and the woodworker Jing-Teng Lin collaborated to implement the shredding-and-mixing design method for material tinkering (Figure 15 and Figure 16). The actual implementation of the design was conducted separately by each designer. First, Lu processed the shredded banana-fibre material into a quantified scale and form for material tinkering and revised the model prototype design to establish a more realistic scale for future mass production. Subsequently, Lin, who specialises in fine woodworking, applied a woodturning technique to create the wooden mould required for design development, thereby ensuring the completeness of the prototype design concept (Figure 17). The researcher held two discussions with the participant in each case. During this phase, pulp was not added to the banana-fibre material. Instead, the participants referenced the “tinkering” concept applied by designers and used short banana fibres to replace the function of pulp fibre. The recomposite material, which was created using shredded banana fibre, was used to tinker and replace waterproof sections. Therefore, a waterproof coating that consisted of beeswax and isinglass was applied to the surface of the material to achieve the set functions required in disposable utensils that use the new material.

Mould processing is a common practice among craftspeople and designers. Through the proposed design implementation framework, both participants quickly reached a consensus regarding the shape of the mould to use. Throughout the process, the participants repeatedly tested various proportions of long and short fibres in creating the optimal material structure after completing the water-pressing process (Figure 18).

6.1.3. Case 3: Continued Application of Creative Composite Material Design

The design student SA reviewed prior knowledge and referenced how CA and DB tinkered the dried banana-stem material. CA used iron wires and wooden boards for plate fixation to thoroughly spread the material and prevent wrinkles caused by the loss of moisture during the fibre drying process (Figure 19). By contrast, to retain the original material structure, DB used adhesive coating (e.g., white glue, epoxy, and super glue) to prevent the material from turning yellow and shrinking as a result of oxidisation (Figure 20). Accordingly, the design vision set by SA for the new material was to process banana stems into quantifiable processing materials and to devise the optimal processing method for material drying. Figure 21 compares SA’s records for samples dried using various fixation methods, namely, needle, plate, and fixture fixation. The records reveal that the combination of the plate fixation with the use of threads effectively produced the optimal material output. Additionally, the material retained optimal quality after thread removal.

SA’s design records indicate that the visual experience presented by the texture of the plant material was incorporated into the design concept. For example, the image of hands of bananas was extended into the fibre pattern of the product. SA applied the tinkered material to the design prototype to ascertain the necessary design adjustments required for the design or material (Figure 22). However, because of time constraints, the design implementation of the present study only resulted in the creation of a sample of the design model using the final material with the wave-shaped pressing mould. The material was dried using a clamping plate, and the material surface was covered with a silicon coating (in accordance with the method applied by DB during the material-tinkering breakthrough stage) to retain transmittance of the material and enhance its waterproof properties (Figure 23).

The design developed in this case accounts for the inconsistencies in the scale of natural materials. After completing numerous sessions of material tinkering, the participant chose to use the wave-shaped pressing mould to mould the material surface. By using the parameter design function of Grasshopper 3D, the mould could be quickly adjusted using the parameters of the processing material, thereby overcoming the limitations of using natural materials for production.

6.2. Applying Material Exploration to Generate Sustainable Benefits

To explain the new knowledge obtained from the design’s implementation and research, the present study first detailed the set development vision for material exploration without any preconceived conditions. The key focus points related to design, technology, and applications were established on the basis of the designs, observations, and records of the participants with respect to the material-tinkering process and the discussions between the researcher and participants. Figure 24 describes the procedures of Case 3 and provides detailed notes for comparison with the grounded-theory analysis results. Through this process, a new development vision for the material was formed. For example, the fixation method used for material drying in Case 3 was crucial; the material must maintain its integrity after drying, and the wrinkles caused by drying must be minimised. Additionally, the core problem of the present study is how banana fibre, an indigenous crafting material with cultural meaning, could be applied in design to create a continuous, systematic, cumulative, or evolutionary creative effect. Notably, every design project must derive a new design vision for the material on the basis of the previous model. Future studies should explore other material-tinkering methods or the evolution of material-tinkering design.

Figure 24 provides annotations based on the axial codes of the grounded-theory analysis. The prototype index highlights crucial problems that were encountered when the banana-fibre material was applied in sustainable product design. Several annotations were simultaneously expressed in the experiences reported in the other cases. These problems carried a specific meaning in the discussion of the design implementation for each case. For example, the use of moulds was considered to be related to the quantisation and productization of materials in accordance with the design implementation framework. Additionally, material processing (i.e., drying) was the main challenge for natural materials. Material drying was involved in all cases, although each participant developed their own design by applying their own drying method. Therefore, the material drying method is a crucial aspect in the sustainable design of natural-fibre materials.

The expression of concepts related to the prototype for design implementation and flexibility is essential for such underdeveloped design experiments that are based on natural materials. Relative to synthesised materials, natural materials are less stable, resulting in unanticipated conditions occurring during the experiment due to the use of different parts of such materials and the methods through which they were extracted. Therefore, creating a prototype sample is a highly challenging task for designers, particularly when the design enters the market, at which point the natural materials that are used are evaluated on the basis of consumer understanding and acknowledgement.

Communication is crucial in the design field. Regardless of whether the participant has a prior background in material exploration or in material tinkering, records of material-tinkering examples (Figure 13) can provide participants with crucial material-tinkering information or ideas for innovative breakthroughs in the material-tinkering loop, thus expanding design options and opportunities. Similarly, to how designers play the role of a chef in the material-tinkering process, the aforementioned records play the role of a recipe and serve as a crucial communication medium for various participants.

7. Conclusions and Discussion: Continued Use of the Design Implementation Method

The present study explored how banana fibre can be transformed from a crafting material used among indigenous communities into a cultural asset for the contemporary era as well as a sustainable crafting material that can be created using agricultural waste. At the present moment, given their knowledge gap compared with the craftspeople, designers cannot systematically understand and process the material; hence, they miss an opportunity to convert banana fibre into a sustainable crafting material for modern products. The present study attempted to address this by introducing MDD to (i) help designers conduct material exploration, thus providing them access to local banana-fibre craftspeople (i.e., stakeholders) who can assist them in further understanding the material preparation process and application opportunities for the developed material (Appendix B); (ii) convey a specific image of the material for designers to think further by ground-theory analysis; and (iii) clarify the context of the design clues and assist designers in sorting out comparisons and references for their design practice process.

Ground on the MDD methodology, this study developed a material-tinkering loop to facilitate the realization of the fourth step (creating material / product concept) of MDD. For the specific case studies presented in this paper, designers practiced their design systematically with their own unique insightful observations, previous technical expertise, and digital assistance. The research results on MDD focused on the relationship and records of the materials used in the design processes and the experiences of users, whereas in RtD, annotated portfolios can serve as a knowledge medium for clarifying how search records are used in design to identify alternatives. Both the MDD and annotation portfolios conducted in this research can assist designers in developing new designs.

This research mainly focused on banana fibres and Taiwan’s indigenous culture in studying the flow of material, which is the process of extracting banana fibre as a material, the inheritance of those techniques, and innovation from tradition. Thus, in this research, the issue of the flow of consciousness was less involved; the indigenous totem culture and the wisdom of applying daily necessities was not emphasised in the examined case studies. In future work, the research will attempt to go a step further in improving the treatment technologies of banana-fibre material-tinkering; it may help to enhance the consideration of mythological stories and the needs of local life in addition to including more local colours and cultural elements to strengthen the design derivation of traditional craft. Accordingly, these methods can support designers in determining the possible applications and potential purposes of these materials, thus enhancing the connection of designers with the development of specific materials and the attainment of a deeper understanding of the material.