Mummy portraits have been discovered in the Egyptian desert from the 1880s onward and ever since then have fascinated scholars and the general public alike. Perhaps this is because they, as T. Potts describes in the foreword of the present book, “depict men and women who lived and prospered two thousand years ago, yet the experience of looking at them feels hauntingly immediate. Their wide eyes return the viewer's gaze, and their expressive faces seem almost familiar” (vii). Nearly a thousand are known worldwide, comprising an extensive corpus of paintings from Roman Egypt produced during the 1st–3rd c. CE.
The portraits have attracted a great deal of scholarly attention, which has led to publications and special exhibitions. These have primarily focused on a variety of aspects ranging from cultural context and chronology to the types of individuals represented, their attire, the sites where the portraits were discovered, and their pictorial tradition and style. There have been very few publications that have investigated the detailed techniques of the portraits’ production and materials. There are some important exceptions to this: for example, A. Freccero's publication of the scientific analyses of the mummy portraits in the National Museum of Stockholm, and the Tebtunis project at Northwestern University, Illinois.Footnote 1 Moreover, various individual articles have dealt with the scientific examination of mummy portraits.Footnote 2 Notwithstanding these important contributions, a comprehensive publication focusing on the technical aspects of this group of artifacts is still needed, especially given the advances made in the study of the techniques of art history over the past decade. This publication now remedies this deficiency by presenting 18 contributions that, on the whole, concentrate on the techniques used to produce mummy portraits.
The papers are the result of the first APPEAR (Ancient Panel Paintings: Examination, Analysis, and Research) conference, held at the J. Paul Getty Museum at the Getty Villa in Malibu, May 17–18, 2018. The APPEAR Project investigates ancient panel paintings to discover more about their materials and manufacture. Launched by the J. Paul Getty Museum's Department of Antiquities Conservation in 2013, this international collaboration addresses the many questions that surround ancient panel paintings.
The APPEAR initiative was developed to create a platform for expanding the knowledge and understanding of the materials and technology used to produce these distinctive works of art. It has adopted a highly collaborative approach both to encourage scholarly research and to support the exchange of technical data and discoveries. Each institution researches its own collections and contributes results to a shared database. Currently, 47 museums from the United States and Europe are participating. They have together contributed several hundred entries to this shared database, which records the technical, scientific, and historic information on the individual portraits. The database provides a unique and compelling opportunity to compare artifacts, to research results, and to accumulate knowledge. This in turn helps develop a broader understanding of the production, materials, and workshop and artistic practices that together created ancient panel paintings. The use of such collective data allows more detailed studies to be incorporated into a larger corpus of information. This facilitates the identification of trends, enabling comparisons to be made and new light to be shed on the use of specific materials, techniques, and the like, thereby enhancing the understanding of this group of artifacts.
This endeavor is to be commended highly; one can only hope that similarly inclusive initiatives are developed for other groups of archaeological polychrome artifacts. To support this generous sharing of knowledge, this publication is being made freely available as an e-book that will be easily accessible to students and scholars worldwide.
Beyond mummy portraits
The APPEAR collaboration began with a focus on mummy portraits but has since expanded to include other painted artifacts in the Romano-Egyptian tradition such as textile shrouds, wooden framed panels, doors, shields, and stucco mummy masks. Nevertheless, the large majority of the studies included in this publication concern mummy portraits, with only three papers on other artifacts. One focuses on six mummy shrouds (discussed below). The second, by G. Borromeo et al. (chapter 9), presents an excellent study of three wooden panel paintings from Fayum, still preserved in their original frames. These fascinating panel paintings, of which only about 60 are known worldwide, provide unique insights into the existence of framed paintings during the Roman Imperial period.Footnote 3 Gods and goddesses form the primary subjects of the panel paintings from Roman Egypt, and the sites where they were found indicate cultic significance in both temples and domestic situations. They thus depict entirely different subjects and served completely different purposes from the portraits which covered the faces of the mummified bodies of the deceased. Panel paintings therefore contribute important knowledge about aspects of ancient painting which the mummy portraits alone cannot. However, with the notable exception of publications by Rondot and Mathews, this group of artifacts has so far not received much attention from scholars.Footnote 4 Hopefully, the APPEAR collaboration can rectify this situation by providing new information about these extraordinary artifacts.
The third paper to focus on artifacts other than mummy portraits is by A. Gunnison et al. (chapter 16). This concerns three fascinating 3rd-c. CE wooden shields with painted scenes from the Trojan War. The shields are from Dura-Europos and are thus outliers in the APPEAR collaboration, but they nevertheless provide an excellent opportunity to compare similarities and differences in materials and techniques across regions.
Artists’ materials
The main and perhaps most important part of this publication deals with the technical art history of mummy portraits: i.e., the materials used by ancient artists to create these painted artifacts. The vast majority of the chapters focus on the analysis of pigments, binders, or substrates, the three constituents of ancient artworks. The analytical methods in this field of research have greatly advanced since the turn of the century. This has made available an array of sophisticated new techniques for the detection and analyses of the components of ancient polychromy, which in turn has reduced the number and size of samples necessary for testing. Moreover, the accuracy of the results has greatly improved, allowing more answers to increasingly specific questions about composition. The following discussion of artists’ materials has been divided into three parts: pigments, organic binding media and coatings, and substrates; several papers consider more than one of these components.
Pigments
The examination and analysis of pigments has taken a quantum leap during the past decade. This is largely due to the introduction of non-invasive multispectral imaging (MSI) techniques, which have revolutionized the study of ancient polychromy.Footnote 5 The research team at the British Museum is among the frontrunners in this field, and in 2009 introduced the now widely used technique of visible-induced luminescence (VIL) for the examination of archaeological polychrome artifacts.Footnote 6 This was followed in 2013 by the useful manual Multispectral Imaging in Reflectance and Photo-Induced Luminescence Modes, which made their standardized methodologies for both the acquisition and the post-processing of multispectral images available to the wider research community.Footnote 7 Other institutions have developed similar manuals, most notably the American Institute of Conservation's 2011 guide.Footnote 8
Many museums and research institutions have adopted these non-invasive methods of pigment detection and tentative identification in their research. Not only are these methods non-invasive and relatively straightforward to perform, but they also use equipment that most major museums can afford. In addition, the results are captured in images that are potentially suitable for dissemination to a wider audience.
Current research into the potential of MSI for artifacts is presented by J. Dyer and N. Newman in chapter 6. This contribution provides a useful overview and illustration of the different MSI techniques currently used at the British Museum and how they are set up. A two-page display and an illustration of the workflow, as well as several color examples of recordings of the 26 examined mummy portraits from the collections of the British Museum, provide an excellent introduction to carrying out MSI and the potential of such techniques for the detection and mapping of several pigments: Egyptian blue (EB) (using VIL), pink lake (using Ultraviolet-induced visible luminescence [UVL]), carbon black, ochers, lead white, indigo, and copper-based greens.
It cannot be stressed enough how powerful a tool these technically accessible methods are for surveying archaeological collections. This is especially so since they provide a holistic overview that is invaluable in assessing the distribution of specific materials, an aspect not always achievable using point analyses. They are particularly significant when sampling is difficult or impossible. The British Museum's excellent research and developments in this field show exciting potential.
The contribution by L. Bradley et al. (chapter 7) similarly focuses on MSI, specifically the relatively new technique of multiband reflectance (MBR). MBR is a straightforward and low-technology photographic method for detecting pigments such as indigo and for mapping their location on an artifact.Footnote 9 The latter is helpful in areas where colorants have been mixed and in places where the original color has faded or discolored over time. Given that there are so far very few references to, or published studies about, this technique,Footnote 10 the team not only applied the MBR method to the examination of six mummy portraits but also investigated the technique itself and compared its results with those of other analyses. The study showed that minute amounts of indigo are difficult to visualize via MBR and that the aging of the pigments and/or binding media may affect indigo's MBR response. Hopefully, additional imaging and analysis of mummy portraits may address such questions about how aging impacts MBR detection of indigo.
Another important result generated by this study is the observation that other blue materials – including lapis lazuli and ultramarine, cobalt-containing blues such as cobalt blue, smalt and cerulean blue, and, to a lesser extent EB – can also produce brightness in MBR images due to their reflectance behaviors (71). As suggested by the authors, it is possible that new combinations of filters may target some of these individual pigments which have pronounced changes in reflectance within the ultraviolet, visible, and infrared spectral regions. This is potentially of great importance for research into ancient pigments, since such MSI techniques may allow for the identification and mapping of additional pigments. The implementation of further MSI techniques can potentially also help remedy the current bias in pigment identification based on MSI techniques, due to the efficient and now widely employed technique of VIL imaging, which makes it possible to non-invasively detect EB even in concentrations invisible to the naked eye.
Three papers each focus on an individual color or pigment, albeit using different methods of analysis and with entirely different goals and perspectives. The first, by R. Newman and G. A. Gates (chapter 3), concerns the red colorants obtained from the different species of madder that were used for dyeing textiles and as lake pigments for painting artifacts from around the late 3rd or early 2nd millennium BCE onwards (27). In mummy portraits, madder appears to have been the major pigment used for pink and purple draperies, for highlights on faces and hands, and for flowers or wine. The paper addresses the various methods used to analyze and identify madder lakes, specifically hydroxyanthraquinones (HAs), the chemical compounds responsible for the color. While the presence of madder is often tentatively identified with UVL imaging, Newman and Gates have analyzed three samples from two mummy portraits and one mummy shroud using high-performance liquid chromatography/mass spectroscopy (HPLC/MS). The results identified the HAs as pseudopurpurin and purpurin for the two mummy portraits, respectively, while the shroud was decorated with a madder containing pseudopurpurin, smaller amounts of alizarin and purpurin, and possibly rubiadin (32). This illustrates how instrumental analysis of samples may provide not only specific identifications of HAs (and hence indications of madder species) but also insights into the lake substrate. The study illustrates that, although imaging offers a powerful and important tool with which to examine ancient polychromy, the combination of imaging with chemical analysis can produce much deeper insights into the materials and production techniques used.
This research also promises to enhance the currently meager information about the ancient use of lakes made from insect dyes (e.g., kermes or lac). So far, there are very few identifications of such lakes used for ancient polychromy;Footnote 11 more is known about the use of insect dyes for textiles.Footnote 12 This overlap between the colorants used for painting and dyeing might indicate closer ties between these craft traditions than hitherto suspected, a possibility that merits further investigation.
The paper by C. Roberts (chapter 4) concerns the use of green pigments in Greco-Roman Egyptian art. Roberts's study includes an examination of six mummy shrouds using various analytical methods. Roberts demonstrates the sheer variety of greens that may be encountered on an artifact, as well as the range of analytical tools required for green pigment identification: green is notoriously difficult to characterize and identify according to type of pigment. Her research demonstrates an interesting diversification in green pigment use and the introduction of a wider palette during Egypt's Ptolemaic and Roman periods: during these periods, a shift in pigment selection happened, demonstrated by the increased use of blue and yellow paint mixtures as well as by green earth, while copper-based greens appear to be absent from the shrouds.
G. Thiboutot's paper (chapter 5) provides an overview of different aspects related to the alluring pigment Egyptian blue. Thiboutot has conducted a useful survey of the portraits in the APPEAR database, focusing on the use and application of EB. She found that at least 44 portraits (out of 284) in the database have revealed the use of EB (identified by VIL imaging), a pigment only surpassed in frequency by ochers. Only two blue colors are known to have been used for the mummy portraits: EB and indigo. These two were not mutually exclusive; both can be found in the same portrait. EB is mostly used in a mixture with other pigments to produce purple, green, white, gray, black, etc., and only rarely to render blue. Moreover, it appears that EB is more likely to be painted in encaustic, possibly indicating a correlation between EB and wax binders. This is a significant discovery because very little is yet known about the relationship between specific pigments and binders. Thiboutot's survey also illustrates how EB was used throughout the whole period of production of painted mummy portraits and can be found in portraits from all the major find sites (i.e., it was used at all the known production centers). In short, EB appears to be omnipresent. Yet some caution is perhaps needed, since the now widespread implementation of VIL imaging may create a bias toward an overrepresentation of EB compared to the other pigments, which tend to be harder to identify.
As the world's oldest synthetic pigment, EB was used at least as early as the First Dynasty of Egypt (from ca. 3000 BCE), possibly earlier, while its latest production and use is still debated. The (so far) latest-known use of EB pigment is documented on an Italian oil painting from 1524 by Ortolano Farrarese.Footnote 13 As more artworks are examined, evidence is likely to emerge of its later use. Nevertheless, there is little doubt that, after the fall of the Roman Empire, the use of EB decreased dramatically for reasons as yet unknown, but it never went entirely out of use. It is difficult to explain why the use of EB pigments, one of the prime pigments for painted decorations for hundreds of years, declined so drastically after the Roman Empire. Perhaps the administration of the major production sites vanished, leaving the task of supplying blue pigments to only a few manufacturing sites, causing their eventual decline.Footnote 14
At present, little is known about the ancient production centers and the sources of raw materials for EB.Footnote 15 However, recent research has focused on lead and copper isotope analyses of the copper used for the pigment's production.Footnote 16 A study of ancient artifacts of Egyptian, Etruscan, Canosan, and Roman origins (dating between the 5th c. BCE and the early 1st c. CE) has illustrated how copper sourced from various European (Aegean, Balkan, Iberian, Central European) deposits potentially supplied EB pigments.Footnote 17 Interestingly, the Egyptian EB pigments studied show no overlap with Egyptian copper, but instead with Aegean sources. Given the highly variable copper provenance of the Etruscan EB pigments studied, this could support an argument for the importation of copper raw materials and a consequent local production process based in Etruria. Moreover, it appears that Iberian copper was used for local EB production in Italy at a time when the known large-scale EB production facilities in the Bay of Naples were already active.Footnote 18 It would be exciting to include such isotope analyses in future studies of the EB (as well as the lead white) used for mummy portraits, since this might reveal information about the production of, and raw materials used for, these pigments. It might also potentially shed light on the interaction between workshops, production centers, and trade in and movement of pigments, and perhaps even chronological variations.
Organic binding media and coatings
The organic components of the paint, particularly the choice of binding medium and coating, are equally significant to the understanding of ancient polychromy. The paper by K. Sutherland, R. C. Sabino, and F. Pozzi (chapter 1) contributes an important discussion of the challenges and limitations of scientific studies of ancient binding media. Scholars have been interested in identifying the binders used for ancient painting for decades. However, as the authors state, although the scientific methods and instruments have improved and become more accurate, “we still face daunting challenges in characterizing the binding media” (11). A major concern is contamination, from the original treatment of the mummy, its subsequent environment, or its later conservation treatments. Other concerns include complications due to microbial deterioration, as well as environmental conditions affecting the organic substances.
A further significant challenge is that the variety of techniques and protocols used by different research groups makes a direct comparison of published results difficult (11). There is no “universal” method of organic analysis; each provides more or less optimal sensitivity and selectivity for the detection of a given type of material. Furthermore, a method may be selected according to the outcome that is anticipated (or based on which instruments are available), potentially creating an unintentional bias in the results. A multi-analytical approach, combining complementary information from different methods of analysis, is certainly to be preferred, although this might not always be possible due to the limited amount of sample material available, and the destructive nature of the analytical techniques required for the analysis of binding media. This holds not only for analysis of binding media but for all aspects of scientific studies in this field.
Sutherland et al. also rightly address the semantic issues that have clouded discussions of binding media used for mummy portraits. These paintings have conventionally been divided into two overall groups according to the choice of binding medium: tempera portraits (egg, glue, or gum as a binder) and encaustic portraits (wax as a binder). This classification has traditionally been made based on the appearance of the portrait's surface and the way in which the paint has been added. Such classifications have been informed by scientific data but, as the authors claim, there are still gaps in the technical knowledge as to how the painters made and applied their paint (8). This is illustrated by an investigation into the techniques that produced two portraits from the collection of the Art Institute of Chicago. Prior to scientific analysis, one portrait was believed to be encaustic and the other tempera. However, analysis determined that the binding medium for both portraits was beeswax.Footnote 19 One can only agree that the unqualified use of “encaustic” and “tempera” as binary terms is unhelpful, and that a more precise and objective use of terms would be preferable. The authors therefore suggest that “encaustic” should ideally be reserved for portraits displaying evidence for the use of heat, preferably supported by the identification of wax, while “tempera” should be further qualified as either glue, gum, or egg tempera.Footnote 20
The paper by J. Mazurek (chapter 17) presents a brief summary of analyses of the binding media of 47 mummy portraits from different museum collections.Footnote 21 Using gas chromatography/mass spectrometry (GC/MS), Mazurek demonstrates that animal glue was the preferred medium in the so-called tempera portraits. Of the portraits examined, 32 were identified as beeswax portraits; 21 of these, together with 1 glue tempera portrait on linen, were found to contain oxidation products of an unknown oil which might have been intentionally added. Finally, the study identified the presence of egg coatings on two beeswax portraits and three glue tempera panel portraits.Footnote 22 Although these interesting results shed light on the portraits’ painting techniques and suggest that oil and egg coatings were added in some instances, the article could have benefited from placing the significance and relevance of these results within a broader perspective.
Nevertheless, the results are interesting, particularly the identification of egg coatings, as well as the use of animal glue as a binding medium. Hopefully further analysis using HPLC/MS-based proteomics might reveal the more specific nature of these organic components. For example, an examination using proteomics of a painted fragment of a relief from the so-called Palace of Apries in Memphis, Egypt (589–68 BCE), proved that the animal glue used as a binding medium was made from domesticated cattle (Bos taurus).Footnote 23 Similarly, a study of three Egyptian panel paintings proved the use of animal glue again made from domesticated cattle, specifically cow hide.Footnote 24 Such analyses could potentially reveal the biological origin of the egg used (egg white, egg yolk, or a mixture of the two), the composition of the coating, whether other protein-based materials have been used for the polychromy, and their level of degradation. This would provide information not only about the authenticity of the material but also about the possible maintenance and repainting of the portraits. Since the mummy portraits are from burial contexts, such analyses would potentially reveal insights into the Egyptian cult of the dead during the Roman Empire.
It is essential to confirm the authenticity of examined materials. In the study of archaeological artifacts, one of the main challenges is to eliminate any of the contaminants that may have been applied during later treatments. Knowledge of the conservation history and careful selection of sampling locations are therefore critical to ensure the likelihood that information obtained from the analysis will be useful. This is particularly the case when analyzing binding media, since the most common binders identified so far are beeswax and animal glue, both of which are also among the most ubiquitous historical restoration materials.Footnote 25 For example, F. Petrie describes how he used fresh beeswax to preserve the excavated mummy portraits from Fayum.Footnote 26 Fortunately, it is now possible to date ancient beeswax.Footnote 27
MS-based proteomics and DNA analysis have recently been applied not only to the study of protein-based materials but also to those of beeswax. Current research is investigating the potential of using beeswax as a biomolecular archive to shed light upon the geographic origin of beeswax (and bees), upon the changing diversity of the hive microbiome in modern and historical beeswax, and upon the DNA of the individuals (extracted from fingerprints in the wax) who were associated with the production of these artifacts.Footnote 28 Although still in early development, such methods may help answer questions of authenticity, and possibly reveal information unimagined only a decade or two ago.
MS has also been used to identify plant gums employed as paint binders in artifacts from ancient Egypt.Footnote 29 Compared to the most common GC/MS analytical strategy, this method based on the partial enzymatic digestion of the gum, followed by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS), has been shown to provide information about plant gums, sometimes at the species level of plant source, thus shedding light on the selection of materials by ancient artists, as well as on the related trade routes.Footnote 30
There is thus a wealth of potentially promising methods which could be applied to future studies of panel paintings. However, such analyses require micro-samples, which, although very small in size, should always be approached with care. There is no doubt that the application of GC/MS is the right place to start when seeking to identify the organic components of ancient paintings. But in the event that further sampling is possible, some of the methods mentioned above could potentially provide a much deeper knowledge of ancient artists’ materials.
Wood
Analyses of the substrates for the mummy portraits and panel paintings are just as interesting as those for the paint layers themselves. Since the level of preservation of these artifacts is so remarkable, it is often possible to sample the wood used.Footnote 31 In chapter 2, C. Cartwright presents her study using high-performance scanning electron microscopy of wood samples from 180 mummy portraits, as well as 20 panel paintings, from 35 institutions worldwide. Cartwright's article stands out in this publication not only for her rigorous and thorough work but also for the sheer numbers of analyses that provide the necessary scientific consistency and comparability of results. According to her findings, most mummy portraits were made of lime/linden wood (Tilia europaea) (about 70% of the examined examples), which is not native to Egypt but imported from Europe. Other imported woods include oak (Quercus sp.), cedar of Lebanon (Cedrus libani), fir (Abies sp.), and yew (Taxus baccata). Native Egyptian woods, primarily fig wood (Ficus sycomorus), comprise only about 20% of the identified samples. The choice of lime/linden can be explained by the fact that this wood offers good-quality and straight timber with a cellular structure useful for creating thin, light panels; such qualities are not found among local Egyptian wood species. However, the foreign origin of the wood in most portraits and paintings immediately raises questions as to whether it was imported as raw timber or prepared panels, or even entirely crafted in Europe.
The study of the Heron panel in chapter 9 includes an identification of the wood: sidr (Ziziphus spina-christi). The study examining 11 mummy portraits from Tebtunis (chapter 14), likewise involved wood analyses, which proved that 9 of the portraits were painted on sycamore fig panels. This leads to further questions which will hopefully be addressed in future studies of wooden Egyptian artifacts, particularly the considerations behind choices in wood for mummy portraits (possibly from different sites and workshops) versus other wooden artifacts. It would be interesting to know whether other wooden artifacts show the same preference for specific types of wood or different preferences based on, for example, type of artifact, context, geographical area, or chronological period.
Egyptian mummy portraits and Greco-Roman polychromy
Knowledge of Romano-Egyptian mummy portraits and panel paintings is highly important not only in itself but also with respect to research into ancient Greco-Roman polychromy. It is now an established fact that ancient Greek and Roman stone sculpture was originally painted.Footnote 32 As the polychromy of these artworks has today mostly disappeared, usually leaving only minute traces, if any, of their original richness of colors, scholars often turn to parallel material for comparisons and insights into what Greco-Roman art might have looked like and how it might have been produced.
In this respect, Roman panel paintings from Egypt, especially mummy portraits, are a vital resource. The mummy portraits provide important parallel sources of knowledge not only about ancient painting techniques and materials, particularly on wood and textile (materials mostly lost from the Mediterranean area), but also about painting on stone. Many of the same pigments were used on panel paintings and Greco-Roman stone sculptures. For example, the use of EB is similar to the Roman artistic tradition, which suggests strong material, technical, and aesthetic ties across the Mediterranean (49). This is not surprising, considering the intense and close contact and trade in this region. However, due to the well-preserved nature of panel paintings, they can often reveal a wider palette of inorganic as well as organic pigments; this has the potential to encourage the search for the same colorants in Greco-Roman polychromy and to identify a potentially available palette. Moreover, the organic components of the polychromy (the binding media and possible surface coatings), which are highly significant to the final appearance of the polychromy, are far better-preserved on panel paintings than on Greek and Roman materials, where such identifications are rare and relatively scattered.Footnote 33 The same clearly goes for painting techniques, such as how the paint was applied, brushstrokes, underdrawings, etc. (see, e.g., chapter 8). Mummy portraits and panel paintings thus provide exceptionally good insights into the final appearance of artworks, particularly portraits, not only from North Africa but from across the entire Roman Empire.
Mummy portraits are therefore also used as inspiration for polychrome reconstructions of marble artworks from Greece and Rome. One example is the reconstruction carried out at the British Museum of the so-called Treu Head, an original 2nd-c. CE ideal female portrait in Parian Lychnites marble.Footnote 34 The head retains rich traces of its original colors and therefore occupies a prominent place in the discussion of ancient sculptural polychromy. The study developed a two-dimensional digital reconstruction of the head's original polychromy based on careful scientific examinations and “selected and particularly appropriate ancient parallels” (especially mummy portraits from Egypt).Footnote 35 Many similarities were observed between the Treu Head and two mummy portraits in particular: the skin tones, the shadows and the highlights, the eyes, and the mouth of the True Head were executed in a very similar way to 2nd-c. funerary portraits from Egypt.Footnote 36
This method of comparison was chosen because the extent of the pigment surviving on the head was too limited to allow a satisfactory reconstruction. In order to exclude a modern reinterpretation of ancient painting techniques, the color reconstruction proposed was created by digitally stretching and deforming images of mummy portraits that show paint layers similar to those observed on the Treu Head.Footnote 37 Such a detailed comparison between the pigment palette and painting technique applied to the Treu Head and to the mummy portraits may provide important insights into the actual appearance of some of the painted marble sculptures, which, as the creators of the reconstruction state, “could perhaps be considered as ‘three-dimensional Fayum portraits’ in terms of visual effect.”Footnote 38 Although this statement is open to debate, there is no doubt that the Egyptian mummy portraits offer huge potential for unlocking the intricacies of polychromy across the entire Greco-Roman world.
Sculptures in marble or bronze are very different from painted wooden panels, and it is not difficult to imagine that different, specialized workshops producing two- and three-dimensional portraits existed during the Roman period. Nevertheless, the craftsmen used the same materials, which suggests overlaps in production that are important to understand more fully. A more nuanced knowledge of the materials and techniques used for mummy portraits will potentially help improve any experimental reconstructions of polychrome sculpture.
Mummy portraits therefore yield an invaluable source of information about ancient polychromy, regardless of geographical area. So too does this publication, which is intended not only for specialists in the study of mummy portraits but for a wider academic audience interested in the techniques of ancient art history, and particularly in colors, painting methods, and polychromy. I expect the next APPEAR conference, planned for 2022, will result in an equally inspiring publication.
Acknowledgments
I am grateful to my colleague Amalie Skovmøller for our discussion of this topic. She has provided me with many important insights into the production of Roman polychrome sculpture and experimental reconstructions. I would also like to thank Clara Granzotto for sharing her impressive expertise in the analysis of ancient Egyptian binding media and coatings. Warm thanks are also due to my colleague Jens Stenger for commenting on earlier drafts of this review.
