**1. Introduction**

*Jazz*, the artist book illustrated by Henri Matisse and published by Tériade in 1947, is considered a defining moment in the life of the artist, when his *papiers découpés*, or paper cut-outs, took a life of their own as a new medium in his practice. Matisse's first cut-outs were maquettes for the cover of Christian Zervos' *Cahiers d'Art* nos. 3–5 in 1936 and for the first cover of Tériade's rival publication *Verve* in 1937 [1]. Encouraged to create a *livre d'artiste* in a similar style by Tériade [2], Matisse composed a series of twenty maquettes between August 1943 and March 1944, with " ... figures in vivid and violent tones, resulting from crystallizations of memories of the circus, popular tales or travel" [3]. In 1947, after several trials and sustained insistence from Tériade, the maquettes were ultimately reproduced and printed by Edmond Vairel and Draeger Frères, Paris. As stated in the last page of the *Jazz* book, the plates were reproduced using a stencil method

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**Citation:** Martins, A.; Prud'hom, A.C.; Duranton, M.; Haddad, A.; Daher, C.; Genachte-Le Bail, A.; Tang, T. *Jazz* Colors: Pigment Identification in the Gouaches Used by Henri Matisse. *Heritage* **2021**, *4*, 4205–4221. https://doi.org/10.3390/ heritage4040231

Academic Editor: Diego Tamburini

Received: 26 August 2021 Accepted: 29 October 2021 Published: 4 November 2021

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**Copyright:** © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

also known as pochoir [4], and using the same Linel gouaches Matisse had used for the maquettes. While he approved of the production technique and proofed all plates, Matisse initially disliked the final appearance of *Jazz*, lamenting to a friend " ... It is absolutely a failure" [5]. Nevertheless, the process itself influenced his future work, where the cutouts became an end to themselves rather than preliminary models for future work. The maquettes are now part of the collection at the Musée National d'Art Moderne in Paris (MNAM), and a total of 250 books, 100 portfolios, and 20 non-circulated copies are in collections and repositories all over the world [6]. The fifth plate in *Jazz* is reproduced in Figure 1 to illustrate the vitality of the work.

**Figure 1.** Henri Matisse *Horse*, *Rider and Clown*, from *Jazz* 1947. One from a portfolio of twenty pochoirs (42.3 × 65.5 cm). Published by Tériade, Paris and printed by Edmond Vairel, Paris, Draeger Frères, Paris. Edition of 100. MoMA object number: 291.1948.5. Copyright © 2021 Succession H. Matisse/Artists Rights Society (ARS), New York. All reproductions of this work are excluded from the CC: BY License.

A full understanding of the materials used in the reproduction of *Jazz* is important and long overdue because of its significance and reach. It is vital that institutions continue taking the necessary precautions when exhibiting and storing *Jazz* to ensure the integrity and vibrancy of its colors.

While systematic studies on the composition of commercial paints used by artists abound: Bocour [7], HKS, W&N, and Maimeri [8], Talens [8,9], and Ripolin [10] to only cite a few, no such studies appear to have been carried out for commercial gouaches. Information in the literature on the Linel gouaches used by Matisse, for instance, is essentially limited to light sensitivity, and no studies were found in the literature concerning the Sennelier gouaches which he also used in his early cut-outs [11]. Matisse was aware of the fading of some of these colors, in particular, the organic-based violets and pinks [12]. Fading of the blues, on the other hand, has been established visually and by spectrophotometry in *Blue Nude I* and *The Swimming* Pool [11,13], while the colors in *Acanthes* appear to be relatively stable based on microfadeometry [14]. The same technique established that of the colors present in *The Snail*, the green, orange, white, and magenta are light-sensitive [15]. A set of cut-out scraps from Matisse's studio, donated to MoMA by the artist's family in 2013, was also recently tested and showed a range of light sensitivities between fugitive and stable [16]. Until now, and to the best of the authors' knowledge, neither chemical nor light stability analyses have been extended to the gouaches used in the printing of *Jazz*. Therefore, any information on the composition and stability of these gouaches is expected to be of interest to the institutions and collectors holding a copy of *Jazz*.

This article reports on a comprehensive analysis of the colors used in three reproductions: a portfolio in the collection of the Museum of Modern Art in New York (MoMA) and two books in the Musée National d'Art Moderne de Paris (MNAM), one in the collection and the other one in the study collection. The objective of the study was twofold: on the one hand to gain knowledge on the nature of the pigments present in the gouaches and their light sensitivity, and on the other hand, to support the assertion that all the copies of *Jazz* were made with the same gouaches. This is also part of a larger study that aims at comparing the materials used in the original cut-out maquettes made in 1943–44 and the pochoirs made in 1947, and also compare these materials with the wider set of cut-out scraps donated to the museum. The identification of the pigments relied on a multianalytical approach using non-invasive techniques including portable X-ray fluorescence (p-XRF), reflectance spectroscopy (RS), reflectance Fourier transform infrared spectroscopy (r-FTIR), portable Raman spectroscopy (p-Raman), and microfadeometry (MFT) and was complemented with analysis of micro-samples by Fourier transform infrared spectroscopy (μ-FTIR) spectroscopy, confocal Raman spectroscopy, and surface-enhanced Raman (SERS) spectroscopy. Principal component analysis (PCA) was used as a data exploratory method to identify gouaches with similar p-XRF, RS, and r-FTIR spectral signatures and help establish the number of gouaches used by Vairel to reproduce *Jazz*.

#### **2. Methodology and Analytical Techniques**

The books and portfolios contain twenty prints designated here by P1 to P20 in the same sequence they appear in the book. The analyses were performed on a *Jazz* portfolio in the MoMA collection and two *Jazz* books in the MNAM collection. A preliminary examination of the MoMA portfolio under an optical microscope (Figure 2) showed minimal overlap between colors but some cross-contamination by paint splatters at the boundary between different color fields, likely caused by the use of a brush to apply the paints [4]. Analysis and sampling were therefore carried out at least 2 cm away from these boundaries whenever possible. Some of the letters and elements in prints P2, P17, and P19, however, were painted over the colored background. This was taken into account when interpreting the data and was confirmed for the three copies of *Jazz* examined.

**Figure 2.** Details of *Jazz* plates examined under the optical microscope (×10 magnification) showing minimal overlap between color fields and some cross-contamination of gouache particles.

The first phase of the study focused on determining the total number of gouaches used to reproduce the MoMA portfolio using non-invasive techniques. For each of the twenty prints, p-XRF analysis and RS were carried on two to three distinct spots for each color and paper support leading to a total of 228 p-XRF spectra and 396 reflectance spectra. The analysis established that for every color in a print, the composition of the two or three spots analyzed was the same. Based on that conclusion, the number of spots for r-FTIR analysis was reduced to one spot per color for each print (142 spectra). Principal component analysis (PCA) was then used as a data exploratory method to identify gouaches with the same p-XRF, RS, and r-FTIR spectral signatures and help establish the number of gouaches used by Vairel to reproduce the MoMA *Jazz* copy. MFT was also carried out on representative spots for each color to evaluate their sensitivity to light exposure. In the second phase of the project, p-XRF, RS, and r-FTIR analyses were carried out on one of the MNAM copies (one spot for each color) to confirm that the same gouaches had been used as in the MoMA copy.

Pigment identification proved challenging for some of the colors using non-invasive analysis exclusively. Further analysis using p-Raman clarified a few of the unknowns but ultimately sampling and analyses by μ-FTIR, Raman, and SERS were carried out on micro-samples taken from the *Jazz* book in the MNAM study collection to provide a more comprehensive overview of the gouache palette and confirm or complement the non-invasive analysis. A representative micro-sample was taken using a tungsten needle for each of the 39 colors identified by non-invasive analysis and whenever possible from the edge of the plate (the plates that were sampled are indicated in Table S1 in the Supplemental Information document SI).
