Folium in Persian and Islamic Manuscripts (15th–19th Centuries): Historical Significance and Analytical Study

2.1 European Focus: The Craft and Trade of C. tinctoria Dye in Early Modern Europe

Medieval European sources provide detailed documentation on the collection of the plant and the processing techniques used to produce the colourant for illuminated manuscripts. Notable examples include the 12th century CE treatise On Divers Arts by Theophilus (Hawthorne and Smith 1979, 38–40), the 14th century CE Montpellier Liber Diversarum Artium (Clark 2011, 110–111), the 14th–15th century CE De Arte Illuminandi (Brunello 1992, 63–67), and the 13th-15th century CE The Book on How to Make All the Colour Paints for Illuminating Books (Melo et al. 2018). These texts provide thorough descriptions of the plant’s collection and processing methods for manufacturing the colourants used. Furthermore, this knowledge was meticulously preserved in Ms. Parma 1959, a Portuguese text written in Hebrew characters, which likely aimed to assist in the production of Hebrew Bibles illuminated with the colourants described in these sources (Melo et al. 2018). The most recent edition of this treatise was published by Strolovitch (2010).

It is noteworthy that across numerous medieval and early modern treatises and descriptions, a wide array of terms has been used to refer to both the plant and the dye, creating significant challenges in precisely identifying the species involved (Wallert 1990, 141–155). Typically, C. tinctoria was known as “turnsole,” derived from the Latin torna-ad-soleum (meaning “turns towards the sun”). However, it was also referred to as folium, solanum, solsequium, morella, morelle, Heliotropium tricoccum (“heliotrope with three small balls”), dyer’s croton (Croton tinctorium), katasol, maurelle (in French), litmus (UK), lakmus (Germany), and Lakmoes (Netherlands) (Guinot 1996, 30). These terms have historically been applied to a broad range of plants from diverse botanical families, all of which produce hues varying from blue to violet to red, depending on the pH of the solution in which they are processed. The blue-violet dye is derived from the fruits of C. tinctoria (family Euphorbiaceae), an annual herbaceous plant thriving in the Mediterranean basin, North Africa, and Central and Southwest Asia, including Iran (Cardon 2007, 40, 577). This plant commonly grows in dry, disturbed habitats such as fallow lands and edges of cultivated fields, particularly in limestone-rich soils (Figure 1). C. tinctoria typically reaches a height of 10–40 cm, with grey-green, tomentose foliage; erect, branching stems, and rhombic to ovate leaves with sinuate margins (Nabais et al. 2020, 3). Fruiting occurs from late August through September, aligning with the summer season.

Figure 1:

Distribution map of C. tinctoria (turnsole) in Iran and worldwide. Source: Hoseini, S. S., Najafi, G., Moazzez, A. F., Hazrati, S., Ebadi, M.-T., & Yusaf, T. (2020). “Potential of Chrozophora tinctoria Seed Oil as a Biodiesel Resource.” Applied Sciences.

During the Middle Ages, blue and purple dyes were extracted from C. tinctoria and absorbed onto small pieces of cloth known as clothlets, which were then dried. These clothlets, preserved as watercolour-like materials, were utilised later by miniaturists for manuscript illustrations and illuminations. To do so, artists would cut a section of the clothlet and dissolve the colour with a suitable binding agent. The colour obtained was commonly called folium, a term referring to the dye-saturated cloth rather than the plant itself; the clothlets were typically stored between book leaves, or folia, to retain their colour longer. Consequently, folium designated the prepared cloth. In Schedula Diversarum Artium, Theophilus described three hues achievable with folium: a brownish-red colour or folium rubeum, a purple to violet colour or folium purpureum, and folium saphireum, a blue hue; each depending on the environment (acid or alkaline) in which it has been tempered (Hendrie 1847, 43–45). Clarke (2016) notes that “katasol” likely refers to turnsole, particularly in Middle English technical treatises, where it generally refers to cloth used to capture dyes, often but not exclusively from C. tinctoria. However, Melo et al. (2018) argue that, in the chapter 24 of Book of All Colour Paints, “katasol” specifically refers to the dye derived from C. tinctoria fruits.

De Arte Illuminandi provides a detailed recipe for preparing blue folium noting that it lasts up to a year before gradually turning purple (Brunello 1992, 63–67). The author advises preparing the dye protected from sunlight and keeping the cloth in a dry place within books. In contrast, the Book of All Colour Paints instructs exposing the coloured cloth to urine vapours, drying it in sunlight until it achieves a “blackberry” hue. The clothlets should then be stored away from winter air until needed. The recipe also specifies that once tempered with gum Arabic, the dye must be applied immediately to prevent fading (Melo et al. 2018). From the 16th century CE onward, recipes for folium began to gradually disappear from artists’ manuals. Painters increasingly turned to alternative colourants that were both easier to handle and more readily available, either locally or through expanding global trade networks. These colourants included madder, kermes, indigo, and brazilwood, often mixed with lead white.

During this period, however, the folium plant found renewed use in the production of textiles dyed with C. tinctoria in southern France, specifically by the Gallarguois, or inhabitants of Grand Gallargues in the Languedoc region. It was not until the 19th century CE, however, that scientists and botanists were able to travel to this region to examine the plant first-hand, observe the extraction process, and thus correct earlier errors and inconsistencies. Galmiche (2013) comprehensively summarizes the field studies and historical surveys that have sought to identify the precise characteristics of this dye. In his opinion, the most reliable descriptions are those of Montet in 1754 and Père Hugues in 1835. Being pastor in Gallargues from 1838 to 1845, he was in the best position to accurately record the entire manufacturing process (Galmiche 2013, 143, 150–158; Montet 1754, 687–698; Hugues 1996, 160–71).

Hugues notes that this craft has been practiced in the region since at least 1600, and the process was restricted to hot and windy days. In brief, the process was as follows: The fruit was first crushed under a millstone, forming a paste which was then placed in woven baskets and pressed in a press to extract all the juice. Once the juice was collected, human urine was added. Then, the dyer had to proceed rapidly to dye the cloth before the colourant lost its potency. The washed rags were then soaked and kneaded with the hands in the mixture of juice and urine, before being quickly spread on drying racks positioned above layers of horse manure, known as aluminadou. To prepare an effective aluminadou, the craftsman selected manure rich in horse excrement that had undergone substantial fermentation. A layer of manure was covered with fresh straw, and then layered with the rags. The rags were stacked and covered with straw, followed by an additional layer of manure. The rags remained on the aluminadou for only 1 h, as the manure was highly potent; the manufacturer monitored the process closely to avoid overexposure. If the rags were left in the manure’s vapour for too long, they would develop an undesirable yellow hue, rendering the operation unsuccessful. Thus, the dyer removed the rags as soon as they acquired a deep blue tint. The dyed rags were then allowed to dry, with care taken to avoid prolonged exposure to the sun, which could degrade the dye. Under the intense sunlight and strong northern wind, the rags would dry thoroughly. However, if the weather turned wet during the drying process, the dyeing would become ineffective, as the juice, without the heat needed to crystallize it, would fail to become embedded in the cloth fibres.

Alongside the aluminadou process, Montet documented another method in 1754 which involved the use of quicklime. In this method, the rags were first dyed and then left to dry in the sun. Once dried, they were placed in a vat and immersed in urine collected by the village’s women, with contributions from the entire community. Quicklime was then added to the vat, and the mixture was covered with reeds and a large blanket to retain heat. The rags were left to ferment in the urine’s warmth for approximately one day or more. This fermentation allowed the rags to develop the desired blue colour, after which they were removed from the vat (Montet 1754, 692–94).

The dyed cloths, often made from recycled rags of various materials and known as drapeaux in French, were primarily exported to the Netherlands. There, they were employed to colour the outer rind of Edam cheeses in a distinctive red hue, commonly referred to as fool’s heads or cannonballs. The rags were transported from Grand Gallargues to the ports of Sète and Marseille from where Dutch merchants shipped them to the Netherlands. Although no direct records survive in French or Dutch detailing the exact cheese-colouring method, it seems that Dutch farmers applied the dye by rubbing the cheese rinds directly with the rags. This allowed the dye to adhere to the crust, gradually turning reddish-purple due to the acidity of the cheese surface (Galmiche 2013, 378–380). This coloured coating helped preserve the cheese during export, especially to the Dutch colonies. However, the use of C. tinctoria juice for this purpose began to decline in the 1850s, eventually ceasing around 1875 with the advent of synthetic colourants (Galmiche 2013, 380–381).

What distinguishes this enigmatic plant from other medieval European sources of blue-violet dye is its elusive chromatic structure, which has not been understood until recent years, despite extensive research into the plant over the last few decades. (Aceto et al. 2015, 159–168; Degano 2018; Guineau 1996, 23–44; Gettens and Stout 1966; Krekel 1996; Melo et al. 2018; Pozzi and Leona 2015, 67–77; Wallert 1990, 141–155). Finally, recent investigations by Nabais et al. (2020) have revealed the molecular structure of the medieval blue derived from C. tinctoria, composed of the blue dye chrozophoridin, a derivative of the alkaloid hermidin, represented by two isomers, and by several anthocyanins.

Unlike in Iran, where C. tinctoria was used to dye paper for luxury manuscripts and albums, the plant did not enjoy this status in Europe, where its application was primarily limited to paint materials until the late 15th century CE. In France, C. tinctoria, or turnsole, was classified by royal edicts as a “teinture de petit-teint” – a non-permanent dye – unlike more durable colourants such as indigo, madder, woad, and kermes, which were classified as “teinture de grand-teint.” Consequently, the use of turnsole by master dyers for textiles was prohibited in France, confining it to lower-quality, utilitarian materials. While French records contain mentions of maurelle and turnsole for colouring utilitarian paper, these references are often brief and lack detailed descriptions of the processes involved (Diderot et D’Alembert 1751-65, 480; Payen and Richard 1851, 556; Valmont de Bomare 1775, 86). For instance, many sources refer to sugar loaves wrapped in purple or blue paper, intended to enhance the sugar’s white colour and reflect its quality. Although some references cite turnsole as a source of blue dye, most sources indicate that various lichens, widely available in French regions such as Normandy, Auvergne, and Lyonnais, as well as in England and the Netherlands, were the primary materials. Other plants commonly mentioned for blue dyes include woad, indigo, India wood, and Brazilwood wood (Brückle 1993; De Lalande 1761, 79–80 and 86; Robiquet 1829, 236).

2.2 Persian Focus: Traditional Dyeing Practices in Persian Manuscripts

Building upon our previous investigation, the colourants designated for paper dyeing in medieval Persian historical treatises are categorised into two groups: primary colours (mofradāt) and secondary colours (morakkabāt) (Barkeshli 2016, 49–89; Barkeshli, Ataie, and Alimohammadi 2008). Within the primary colours, various shades of blue (kabud) are mentioned, using terms similar to the Latin designation for turnsole used in European sources, such as toḵm-e-ʿalaf-e aftāb gardeš (seed of a sun-turning weedy plant), toḵm-e-ʿalaf-e ḵor gardesh (seed of a sun-revolving weedy plant), and toḵm-e-ʿalaf-e āftāb gardān (seed of a weedy plant that turns towards the sun). These are referenced alongside the use of indigo dye. Within the secondary colours, references to shades of green (sabz) and another type of green (fariseh) are made, with the term kabudak (blue). However, the recipes for green hues, which could refer to either indigo or turnsole, merit separate exploration and presentation in future articles.

The absence of terms like toḵm-e-ʿalaf-e aftāb gardeš, toḵm-e-ʿalaf-e ḵor gardesh, toḵm-e-ʿalaf-e āftāb gardān, and kabudak from contemporary Persian language posed a mystery to conservation scientists and historians regarding the natural local plant being referenced, until our present investigation. Through botanical studies in the region (Mozaffarian 2018; Labbafi 2024), interviews with botanical scholars such as Valiollah Mozaffarian in 2019, and analysis of the recipes, we have determined that these terms correspond to folium derived from the fruits of the C. tinctoria plant. Despite the terms “folium” and “turnsole” are frequently (but incorrectly) used as synonyms in the ancient literature, it is appropriate to clarify that “folium” should be referred exclusively to the dye extracted from C. tinctoria, while “turnsole” must be considered as a popular term for the C. tinctoria plant, also known as dyer’s croton. In the following, the term “turnsole”, instead of C. tinctoria, will be used in the realm of the text of ancient treatises.

The term kabudak likely derives from the ancient Persian word Kabud, meaning blue, while the other three terms stem from “sun-follower,” owing to the flowers’ rotation towards the sun, akin to the behaviour from which turnsole derives its name. In other Persian sources, including botanical encyclopaedias, the plant is referred to by various names such as azraq ازرق (Labbafi 2024) ranginak رنگینک (Labbafi 2024), goosh-barreh گوش برّه (Hammami, Azadi, and Sadrabadi 2018, 157–161), gul-e aqrabi گل عقربی (Noori, Zare Mayvan, and Mazaheri 2012, 118–126), and kabudak کبودک (Mayel Heravi 1993, 59).

There are numerous Persian historical recipes from 15th–19th centuries where material technology of turnsole or C. tinctoria are introduced for obtaining blue dye. The Persian terms that are used for the name of the plant under one of the primary colours (blue), are either Toḵm-e-ʿalaf-e aftāb gardeš, tokhm-e-ḵor gardesh and tokhm-e ʿalaf-e āftāb gardān. Two techniques are described to obtain blue dye from turnsole. The first technique involves processing in moist soil, while the second technique makes use of an earthen pot. In both methods, cloth is soaked in the extract of turnsole fruits exposed to sal-ammoniac (salammoniac, salmiac, ammonium chloride) in Persian called naushādur.

3.1 Collection of Fruits

For the experiment, we collected fruits from early August to the end of September, spanning 2022–2023, covering stages from light green to dark green, and finally to purple. The fruits displayed various colour shades: light to dark green in June–August 2022, and purple in August–September 2023, corresponding to different stages of ripening (Figures 3 and 4). When soaked in water, the unripe light green fruits did not produce any colourant. However, the dark green semi-ripe fruits yielded a rich blue dye that eventually turned purple. The fully ripe purple fruits consistently produced a stable purple dye. We believe these variations were due to the different stages of fruit maturity – raw fruits from the first pick in June 2022, semi-ripe, slightly more developed fruits from July–August 2022, and fully ripe fruits from August–September, which gave a stable purple extract. This observation aligns with findings by Aceto et al. (2015). We also noted that when fresh fruits were soaked in water, the mature purple fruits turned the water purple within 2 h, while the dark green fruits turned the water blue. In contrast, soaking light green fruits did not result in any colour change (Figure 5).

Figure 3:

Fresh C. tinctoria plant from the Telo-Tehran area.

Figure 4:

Unripe and semi-ripe fresh fruits harvested from C. tinctoria plants in the Telo-Tehran area.

Figure 5:

Folium extracted from fresh C. tinctoria plants in different stages of ripening, after soaking in water for 2 h. From left to right: sample of three picked fruits from different stages of fresh C. tinctoria plants before soaking, unripe light green, semi-ripe dark green, and fully ripe purple fruits after soaking in water.

3.2 Preparation of Clothlets

The fruits from intermediate and final stages of C. tinctoria were individually collected for experimentation in August and September 2022–2023, including both dark green and purple fruits. Since Persian recipes do not specify how to extract the dye, we chose to crush a pound of the fruits in a stone mortar and to obtain the extract. Small square pieces of cotton cloth, each measuring 7.5 cm² and weighing 1.4–1.8 g were prepared, soaked in the aqueous extract, and dried in the shade following the Persian historical recipes (Table 1).

The impregnation process could be repeated up to 4 or 5 times. After each drying cycle, the cloth pieces were re-soaked in the extract until fully penetrated, then left to dry in the shade (Figure 6).

Figure 6:

Cloth pieces soaked in the extract of C. tinctoria fruit before being fumigated with sal-ammoniac (naushādur).

Following the extracting, impregnating, and drying process of the cloth pieces, an earthen jar that had not been exposed to water and remained unglazed was selected. Next, 20 g of ammonium chloride (naushādur) powder was poured and mixed with warm water in the jar until it foamed. The jar was then placed in the sun until all dissolved water completely evaporated. All the cloth pieces previously soaked in the extract were placed in the jar and left in the sun for a day until the fabric colourants converted to a deep blue-purple hue (Figure 7).

Figure 7:

The process of making folium clothlets. From left to right: unglazed earthen pot, foamed ammonia chloride, and placing soaked folium cloths in the dried jar impregnated with ammonia chloride.

In the final stage, the fabrics dyed deep blue were removed from the jar, after which they could be stored and used to create dyes in different shades of blue whenever needed (Figure 8).

Figure 8:

Cloths impregnated with the extract of C. tinctoria from different stages of maturity of the fruits after fumigation with ammonium chloride.

3.3 Reconstruction of Paper Dyes Based on Persian Historical Recipes

The dye was extracted from folium clothlets to obtain shades ranging from the primary colour blue to purple (Kabud) following the Persian historical recipes outlined in Hossein Aqili Rostamdari’s Ḵaṭṭ va Morakkab (930–984 AH/1523–1577, 337). The dried folium clothlets were placed in a China bowl, and cold water was added drop by drop to extract the dye. To achieve different shades of colour, as described in Resāleh Dar Bayān-e Ṭarīqeh-ye Sāḵtan-e Morakkab va Kāğaḏ-e Alvān, varying amounts of water were used (Figures 9 and 10).

Figure 9:

Blue (left) and purple (right) dyes extracted from the blue and purple folium clothlets obtained from different stages of maturity of the fruits.

Figure 10:

Left: Extraction of purple folium clothlets. Right: Papers dyed from extracted purple folium clothlets according to Persian historical recipes.

In our experiments, we also explored the time factor by soaking the papers at concentrations of 1:10 for 1, 5, and 60 min to achieve light to dark blue shades of colour (Table 2).

Table 2:

Different shades of dyed paper with blue folium from extracted clothlets in different durations of time.

Blue (Kabud)
60 min	5 min	I min

3.4 Storage and Preparation of C. tinctoria Fruits for Future Use

Since the period for harvesting C. tinctoria fruits is limited, it is advisable to store them for future use. Alongside preparing folium extract clothlets during the season, fresh fruits can be picked and naturally dried or dried in an oven to expedite ripening. To minimise seed popping, the fruits can be dried at lower temperatures (e.g., 50 °C) for longer durations. Ideally, the fruits should be dried in a well-ventilated oven. Once dried, they can be safely stored for years and used as needed for dye extraction.

In our experiments, as shown in the Figure 4, most of the fruits were still green, indicating they were unripe, while some were darker, suggesting a higher potential for developing blue or purple colours. We placed the C. tinctoria fruits in an oven at 80 °C for drying, observing the changes in colour and texture as they dried over 10–11 h, checking on them every 2 h. Interestingly, during the last hour, some fruits began to pop up like popcorn, prompting us to remove them from the oven. While some did pop, the majority remained intact (see Figures 11 and 12). This preparation step is used for the dye extraction process in the next phase of our scientific analysis and lays the groundwork for potential future studies.

Figure 11:

Drying fresh fruits from the C. tinctoria plant in an oven at 80 °C for about 10–11 h to expedite ripening and storage for future use.

Figure 12:

Fruits popping up like popcorn in the last hour of drying in the oven, indicating they should be promptly removed.

4.1 Sample Preparation for Instrumental Analytics

Samples were prepared by extracting the dye from the external cuticles of C. tinctoria fruits. The fruits were collected in Umbria (Central Italy) during August 2023 and allowed to dry in an oven at 80 °C for 10 h; then the external cuticles were taken and subjected to extraction in cold water for 1 h upon stirring. After filtration on paper, the resulting extract was used to paint on parchment.

The samples from Iranian fruits were prepared the same way, after the fruits had been dried as mentioned above locally and sent to the Italian laboratory. In this way, the spectral responses were totally comparable.

4.2 Fibre Optic Reflectance Spectrophotometry (FORS)

FORS measurements were carried out with an Avantes (Apeldoorn, The Netherlands) AvaSpec-ULS2048XL-USB2 model spectrophotometer and an AvaLight-HAL-S-IND tungsten halogen light source; the detector and light source were connected with fibre optic cables to an FCR-7UV200-2-1,5 × 100 probe positioned at 45° with respect to the surface normal. The spectral range of the detector was 200–1160 nm; spectra were collected in the range 350–1100 nm. The spectral resolution was 2.4 nm calculated as FWHM (Full Width at Half Maximum), according to the features of the monochromator (slit width 50 µm, grating of UA type with 300 lines/mm) and of the detector (2048 pixels). Diffuse reflectance spectra of the samples were referenced against the WS-2 reference tile (Avantes), guaranteed reflective at 98 % within the spectral range of interest. The spot size of the investigated area on the sample was 1 mm. The sample-to-probe distance was 2 mm, corresponding to the focal length of the probe. Instrumental parameters were 10 ms integration time, 100 scans for a total acquisition time of 1.0 s for each spectrum. The system was managed by means of AvaSoft v. 8™ dedicated software, running under Windows 10™.

4.3 Surface Enhanced Raman Spectroscopy (SERS)

SERS analysis was performed by means of Ag nanoparticles colloidal pastes (AgNP). AgNP (1 µL) was poured on the sample and allowed to dry before exposing it to the laser beam. SER spectra were collected with a high-resolution dispersive Horiba (Villeneuve d’Ascq, France) LabRAM HR Evolution model spectrometer coupled with a confocal microscope. The instrument was equipped with 532 and 633 nm excitation lasers, a 1,800 lines/mm dispersive grating, a 800 mm focal length achromatic flat field monochromator, and a multichannel air-cooled CCD detector. The spectral resolution is 2 cm⁻¹. Spectra were taken with long working distance 50× and 80× objectives. Laser power at the sample was < 1 mW. Exposure time was 1–10 s according to needs (3 accumulations). The system was managed with LabSpec 6 software running under Windows 10™. For reference, both FORS and SERS spectra were recorded on parchment with aqueous extracts from C. tinctoria violet fruits.

4.4 Comparing Persian and European Folium

Figure 13 shows the FORS spectra (in apparent absorbance coordinates, using the Log (1/reflectance) transform) of folium from violet fruits of C. tinctoria from Italy (green spectrum) and from Iran (blue spectrum). The absorption bands characteristic of folium occur at ca. 549 and 584 nm and allow to selectively identify this dye with respect to other purple dyes such as orchil, madder, scale insect dyes, Tyrian purple, and alkanna (Aceto et al. 2014, 1488–1500).

Figure 13:

FORS spectra of violet cuticles of C. tinctoria extracts from Iran and Italy.

Figure 14 shows the SERS spectra of folium obtained from C. tinctoria from Italy (bottom line) compared to folium obtained from C. tinctoria from Iran (top line). Both spectra align with the spectral features reported in the literature (Aceto et al. 2017b, 48, 530–537).

Figure 14:

SERS spectra of folium obtained from C. tinctoria collected in Iran (top) and Italy (bottom). The bands belonging to AgNP have been pin-pointed.

4.5 Identification of Folium in Manuscripts Produced Under Islamic Rule

The findings suggest discussion as to whether this dye was used in Persian manuscripts, too. It has been already pointed out that folium was widely used in manuscripts produced in Europe, particularly in the Late Middle Ages and the Renaissance (Aceto et al. 2017a, 461–469). However, given the notable corpus of citations of folium in Persian historical treatises, described in the previous sections, it is expected that this dye was also used in manuscripts produced under Islamic rule, which at present, to the authors’ knowledge, has not yet been verified. Recently, the authors of this study were able to find a small, but meaningful number of identifications of folium in manuscript produced outside Europe (Table 3).

4.5.1 Identification of Folium in ms. Copte-Arabe 1

In addition to the experiments carried out in laboratory, recent observations by the authors of this work have shed further light on the use of folium in manuscripts. Our identification of this dye in the palette of ms. Copte-Arabe 1 at the Institut Catholique de Paris (ICP), underscores the significance of our findings (Figure 15). The identification was based on the typical spectral features previously described and on the overall characteristic shape of the FORS spectra.

Figure 15:

Location of the measurement spot to identify folium in ms. Copte-Arabe 1 (f. 65v, white spot) dated 1249–1250 CE, produced in Egypt, kept at the Institut Catholique de Paris, Bibliothèque de Fels.

The manuscript Copte-Arabe 1 is a Four Gospels book written in Bohairic Coptic with a parallel Arabic translation (Baumstark 1915). This manuscript is composed of paper, ink, and pigments, and its dimensions are 255 × 175 × 60 mm. It is believed to originate from Northern Egypt, possibly Cairo, and dates back to 1249/50. The manuscript was acquired in Egypt in 1885 by Émile Amélineau (1850–1915) and was subsequently given to the library of the ICP by Maurice Le Sage d’Hauteroche d’Hulst (1841–1896). It once belonged to a bilingual New Testament codex which now consists in two separate volumes: the first part (Paris, ICP, ms. Copte-Arabe 1) gathers the Gospels of Matthew, Mark, Luke, and John, while the second one (Cairo, Coptic Museum, ms. Bibl. 94) contains the Pauline Epistles and the Acts of the Apostles. The colophon preserved at the end of the second volume (Farag 2023) (Cairo, Coptic Museum, ms. Bibl. 94, f. 216r.) states that the book “was written by the hieromonk Gabriel for the archdeacon and sheikh al-Našū Abū Šakir ibn al-Sami al-Rahib ibn al-Muḥadhab (…) and was achieved the 10th Kyhakh in the year of the Martyrs 966, that is, 1249/50 of the Christian era”. The scribe’s name also appears in ms. Copte-Arabe 1 at the end of each Gospel book, which confirms the dating and attribution of both parts of the original manuscript. See, for example, ms. Copte-Arabe 1, f. 225r: “For God’s sake, remember me, the poor Gabriel, unworthy to be called a monk and a priest, and may God forgive me. Time of the Martyrs 966 (1249/50 CE)”. Traces of the scribe Gabriel are found in a small group of Coptic manuscripts that attest to his activity during the first half of the 13th century CE. Horner (1898–1905, I, 91–92) suggested identifying the scribe Gabriel with the future patriarch Gabriel III of Alexandria, head of the Coptic Church 1268–1271. Whatever one may think of such a hypothesis, the fact that Gabriel III was himself a Syrian appears significant in the context of book production in Egypt during the late Ayyubid period (1171–1250). Ms. Copte-Arabe 1 is indeed considered as a witness of the highest state of painting in Egypt and the allied territory of Syria during the last years of the Ayyubid rule (1218–1250). He also wrote a Copte-Arabic Four Gospels book in 1205 (Vatican City, Biblioteca Apostolica Vaticana, Cod. Vat. Copt. 9) and another one in 1257 (Cairo, Coptic Museum, ms. Bibl. 93). The latter was undertaken in the household of Sheikh al-Amjad, son of al-’Assāl, to which Gabriel had been attached in Syria and Old Cairo for the preceding 10 years. Therefore, it is very likely that ms. Copte-Arabe 1 was written in Cairo rather than in a monastic workshop.

The text of ms. Copte-Arabe 1 has been written before the illustration was executed ( Leroy 1974 and Hunt 1985, 127). However, even if the same scribe wrote the two parts of the original manuscript, the miniatures do not seem to be the work of a single painter (Leroy 1974, 177). According to Leroy (1974), it seems that one major artist undertook the greater part of the illustration of ms. Copte-Arabe 1, while another, less expert hand can be detected in parts of the Luke portrait (f. 105v). This second hand can be compared with the one who painted the frontispieces of ms. Bibl. 94. Further analysis could determine whether these various artists had similar dyes at their disposal, and whether it is possible to distinguish them from the mixtures they produced.

4.5.2 Identification of Folium in ms. BnF Copte 129(11)

The making of ms. Copte-Arabe 1 must be examined within its context of origin, which shows many technical features common to other Coptic and Arabic manuscripts. As such, the use of folium is attested in Egypt as early as the late 10th century CE. Four occurrences of folium were identified by the authors, again according to the typical FORS spectral features, in ms. Copte 129(11) kept at Bibliothèque nationale de France in Paris (BnF), produced in Lower Egypt. This volume of the New Testament that contains Acts, Epistles, and Apocalypse, was written in the monastic workshop of Tūtun, in the Fayyum region, in the last quarter of the 10th century CE. Folium was used in this manuscript at ff. 113r and 113v to obtain different shades of bluish grey, mainly in the zoomorphic decoration of the margins; it was sometimes mixed with indigo for pale grey tones (see e.g. f. 113v, Figure 16). The early date of ms. Copte 129(11) suggests that the use of folium was known in Egypt long before the first Crusade (1096–1099 CE).

Figure 16:

Location of the measurement spots to identify folium in ms. Copte 129(11) (f. 113v, white spots) dated 10th CE, produced in Lower Egypt, kept at the Bibliothèque nationale de France (BnF) in Paris.

4.5.3 Identification of Folium in ms. Arabe 5847

Another, later example of folium use can be found in an illustrated copy of the Maqāmat by Al-Ḥariri produced in Djazirah (northern Iraq) in the early 13th century CE. The luxurious ms. Arabe 5847 (Paris, BnF) was written and painted in 634 A.H. (1236–37 CE) by Yahyā ibn Mahmūd al-Wāsiti, active in Baghdad in the late Abbasid era. The two occurrences of folium in ms. Arabe 5847, identified by the authors by the typical absorption bands in the FORS spectrum, concern a small detail of vegetal decoration, in a light violet tone, and the pale blue robe of a character (see e.g. f. 156r, Figure 17). This identification was based on the typical spectral features previously described and on the overall characteristic shape of the FORS spectra.

Figure 17:

Location of the measurement spot to identify folium in ms. Arabe 5847 (f. 156r, white spot) dated 1236/37 CE, produced in Baghdad, kept at the Bibliothèque nationale de France (BnF) in Paris.

4.5.4 Summary Comments on the Identification of Folium

In Figure 18, the FORS spectra taken from mss. Copte-Arabe 1, Copte 129(11), and Arabe 5847 are compared with the spectra of standard folium obtained from Italian and Iranian fruits of C. tinctoria. Both the spectral features and the overall shape of the spectra are similar, suggesting the use of folium in all cases.

Figure 18:

FORS spectra from the Islamic manuscripts analysed in this study, compared with spectra of folium reference spectra prepared according to historical recipes.