On the Identification of the a fresco or a secco Preparative Technique of Wall Paintings

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper is devoted to analysis of fragments of wall paintings from a Roman villa. Special attention was paid to distinguishing between a fresco and a secco painting techniques based on the presence of organic binders. Several complimentary analysis methopds were used -  SEM-EDS, XRF, FORS, Raman, IR, XRD, GC-MS, LC-MS. Multistage approach incorporating non-destructive, micro-destructive and destructive techniques was proposed. The paper is well-written and should be of interest to Heritage readers. In my opinion, manuscript should undergo a minor revision.

There are two general comments and several specific ones, see below.

 

General comments

1. Section 4.5 contains deneral description of the proposed approach, including Fig. 5 with a scheme of analysis. Authors should consider moving this part of the manuscript to the beginning of “results and discussion” section – to make the comprehension of the text easier. Also, information about the analysis scheme for particular samples should be either added to fig. 5 or provided as a separate figure or table.

2. Authors should summarise the results on the pigments and organic binders identified in the samples. There’s a paragraph (L147-L151) in “Conclusions”, but it will be easier to comprehend this information in tabular or schematic form.

 

 

Specific comments

L 175 – please provide some details on GC-MS analysis.

L 177 – comment should be added that protein extraction was carried out for subsequent LC.

L 228 – authors should add some more comments about layer structure of the samples, phrase “... three layers (pictorial one plus mortar)” is confusing.

L 231 – authors should explain which techniques (PM, XRD, Raman etc) were used for obtaining information on mineral composition of the samples.

L 294 – “The chemical analysis of the layers shows the presemce of calcite, hematite...” – authors should clarify whether these conclusions were made from PM and/or SEM-EDS data. SEM-EDS does not give direct mineralogical information.

P 9, Table 1. Table structure is confusing, consider revising and/or moving part of the data to supplementary.

P 12, L 45 – “Nevertheless, it is worth noting that most likely goethite itself is a product of weather induced conversion of an initial hematite, so the laser-induced Raman spectra might even correspond to the actual starting pigment.” – a literature reference should be given on weathering of hematite.

 

P 14, L 92. Table 3a. Consider moving this and similar tables (3b) to supplementary.

Author Response

Please, see the attachment

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The paper titled "Identification of a fresco or a secco preparative technique in wall paintings" presents a compelling study on the application technique and pigment composition involving inorganic and organic compounds. The study draws from findings during the excavation of a Roman domus in Santa Maria Capua Vetere.

The data are effectively presented, and the conclusions are well-supported by thorough analytical investigations. However, certain aspects need revision, particularly concerning the referenced literature, as reported below.

 

- In lines 51-52 the authors could mention other studies dealing with he characterization of pigments adopting the same techniues, such as:

 

 

- Brecoulaki H, Verri G, Kalaitzi M et al (2023) Investigating colors and techniques on the wall paintings of the ‘Tomb of the Philosophers’, an early hellenistic macedonian monumental cist tomb in pella (Macedonia, Greece). Heritage 6:5619–5647. https://doi.org/10.3390/heritage6080296   

 - Dilaria, S., Sbrolli, C., Mosimann, F.S. et al. Production technique and multi-analytical characterization of a paint-plastered ceiling from the Late Antique villa of Negrar (Verona, Italy). Archaeol Anthropol Sci 16, 74 (2024). https://doi.org/10.1007/s12520-024-01983-w  

- Angelini I, Asscher Y, Secco M et al (2019) The pigments of the frigidarium in the Sarno Baths, Pompeii: Identification, stratigraphy and weathering. J Cult Herit 40:309–316.  https://doi.org/10.1016/j.culher. 2019. 04.021 

 

 

- line 231: what does anatase detection means? this is not common for mortar preparation and should be investigated in detail

 

- Paragraph 4. Results and discussion: lines 207-212. This lines are not results, but methodology. They should be moved in the approrpiate section .

- line 214: do the authors for binder mean "mortars stratigraphy"?: I suggest to change the terminology

- paragraph 4.1, lines 221-226: This lines are not results, but methodology. They should be moved in the approrpiate section .

- Actually the quantification was presuably based of EDS semiquantitative analyses. I would suggest to indicate that the chemical EDS analyses are semi-quantitative and not actually quantitative, even if some correction were done calibrating the instrument on appropriate reference standards. 

- paragraph 4.2., line 25: report the FT-IT spechtra (i.e. as supplementary material)

- Paragraph 4.5.: add some references regarding the mixed fresco (background) with secco (overpaint) technique. This is actually quite common in ancient Roman paintings. Regarding painting microstratigraphy authors could report for example:

- Prisco G. 2005, Su alcune particolarità tecniche delle officine addette alla decorazione della Domus Vettiorum, in P.G. Guzzo, M.P. Guidobaldi (a cura di), Nuove ricerche archeologiche a Pompei ed Ercolano, Atti del convegno internazionale (Roma 28-30/11/2002), Studi della Soprintendenza Archeologica di Pompei 10, Napoli, 355-366.

In general terms, regarding secco and fresco technique authors should mention:

Piovesan et al. 2012, Piovesan R., Mazzoli C., Maritan L., Cornale P., Fresco and lime-paint: an experimental study and objective criteria for distinguishing between these painting techniques, Archaeometry, 54, 4, 723-736.

- Many typing errors were detected. An extensive revision of the text is suggested

Comments on the Quality of English Language

Moderate editing of English language required

Author Response

Please see the attachment

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

This study is comprehensive, employing multiple analytical methods to conduct a scientific analysis of architectural wall paintings in the Campania region of Italy, focusing on inorganic components and organic residues. It also elucidates the production techniques used in these murals. The research methods and the scientific insights uncovered are of considerable importance to the field of cultural heritage studies. However, there are some areas that require attention:

1.       In line 44, animal glue is also a commonly used organic binder.

2.       In the third paragraph of the Introduction, FORS was noted as a common methodology for analyzing wall paintings. The advantages of using Raman and infrared spectra in this study, compared to FORS, should also be explained.

3.       In line 215, Sample 151 was split in three distinct sections (called 151 A, 151 B, 151 C). However, in line 134, Samples 151, 151A, 151B, and 151C are discussed in a parallel manner, which appears contradictory to the split described in line 215.

4.       However, while the mural samples in Figures 1b and 1c appear to be of similar size, it is important to note that sample 151C should actually be considered a part of sample 151.

5.       In Figure 3, the color of the microscope image scale bars should be consistent.

6.       Using more distinguishable colors between lines 5 and 6 in Figure 4 would improve the aesthetics.

7.       In line 194, concerning LC-MS/MS analyses, more parameters of the database search should be provided, including peptide mass tolerance, fragment mass tolerance, fixed modifications, and maximum missed cleavages.

8.       Although the sample consumption for various detections is depicted in Figure 5, this information is not included in the Materials and Methods section. Adding a note such as 'Sample consumption for various detections is detailed in Figure 5' would aid readers in understanding and addressing their concerns.

 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The revised version of the paper is increased and now it can be published. Minor revision of english language required

Comments on the Quality of English Language

Minor revision of english language required

Reviewer 3 Report

Comments and Suggestions for Authors

The revised version is suitable for publication in Heritage.