ART CONSERVATOR
DIGITAL
A PUBLICATION OF THE WILLIAMSTOWN + ATLANTA ART CONSERVATION CENTER
VOLUME 17 NO.1 ILLUMINATED MANUSCRIPTS PART II: Medieval Culture of Bookmaking in Paris
BROOK PRESTOWITZ | ASSOCIATE CONSERVATOR OF PAPER
Initially, illuminated manuscripts were made by the clergy; but by the twelfth century layman artists, scribes, and bookmakers began to dominate the industry [1]. Paris was a major center for learning and the demand from tutors and students for more manuscripts impacted the bookmaking industry. By the fifteenth century, there was an organized system of secular bookmaking studios that made both religious and secular manuscripts. People in trades linked to bookmaking worked near each other in strategic locations within the cities, like cathedrals and universities. In Paris, these trades were located on the IÎe de la Cité on Rue Neuve-Notre-Dameand Rue des Écrivains, present day Rue de la Parcheminerie, on the Left Bank. Many artists and craftsmen were involved in making a single luxury manuscript including parchmenters, scribes, rubricator, gilder, border painters, manuscript painters, binders, and the patron [2]. In some cases a single person was capable of doing several steps. For example, an artist might paint the illuminations as well as the borders and decorative letters or a scribe might write both the text and the rubricing.
The university in Paris realized there was a need to control the quality and pricing of books, both new and used, so they established a new profession called the librarius [3]. The librarius were certified by the university and acted as publisher and intermediary between the patron and the tradesmen [4]. In fact, they were involved in the book of hours industry and offered options for commissioning manuscripts that would meet different patrons’ budgets.
For patrons with a tighter budget, the librarius made prefabricated content available for compiling a low budget book of hours. The prefabricated texts and illustrations were selected based on speculation of what texts were popular at the time. The patrons also had the option to pay a little extra to incorporate a few special texts in these prefabricated manuscripts [5]. This made the popular book of hours accessible to those who were less wealthy while also retaining some aspects of personalization, expanding the librarius’ clientele.
In contrast, luxury books of hours were contracted by wealthy patrons who drew up detailed contracts with artists and librarius. The patron worked closely with those they contracted, dictating the artistic design and the selected texts, following the guidance of their confessor or spiritual advisor [6]. These types of manuscripts were highly tailored to the patron and unique compared to other books of hours. Luxury manuscripts are marked by the quality and quantity of expensive materials, like fine vellum, heavy use of gold and expensive pigments, as well as the quality, size, and quantity of illuminations, borders, and embellished initials present, as the patron was charged per image and letter.
Illuminated Manuscripts Materials and TechniqueS
The folios treated at the lab were made during this time when secular studios were making most of the manuscripts. The fine parchment, excessive use of gold and ultramarine, and the size and quality of the illuminations indicate that the patron of this book of hours was wealthy. This section will describe the process of making a manuscript and compare evidence found in the folios that reflects artists’ practices of that time.
The Parchment Support and Ruling a Manuscript
A very fine, thin, and supple parchment, sometimes referred to as vellum, was used as the support for the folios. The vellum’s quality is captured in its translucency seen in (fig. 1). Parchment manufacturing was involved, dirty work and the processing techniques directly impacted adhesion of inks and paints. The process had to be completed shortly after the animal was killed, beginning with soaking the skins in lime water for some time; removing fat and hair; and stretching them onto a frame to dry (fig. 2). The lime imparts an alkaline pH to the parchment which helps to neutralize acidity that develops in the parchment as it ages, improving its long-term preservation. Parchment processing continued with scraping with a crescent shaped knife called a lunellarium and rubbing with abrasive materials like pumice or dough from a baked loaf of powdered glass, flour, and yeast to develop a fine surface for writing and painting [7]. The parchment surfaces were given a final treatment to reduce fatty residues, improve suppleness, and manage absorbency. Scribes and artists would also apply resins, gums, or glues to the parchment surface to ensure good attachment of their media to the parchment.
FIGURE 1 .
St. Mark folio in transmitted light showing the alignment of text on the recto with the text on the verso. In the top right are diagonal marks that are estimated to be scored lines left from the scraping process of the parchment. Photograph by Brook Prestowitz.
FIGURE 2 .
Parchmenter scraping a stretched skin with the lunellarium parchment scraping knife. Image shared by www.digitalis.uni-koeln.de via Wikimedia Commons.
The construction of a manuscript began with ruling of the parchment where lines were drawn or scored onto the parchment to indicate the formatting of the manuscript contents. While ruling may appear simple and straightforward, there was a considerable amount of careful planning involved in this step [8]. In the case of a luxury manuscript like these folios came from, the artist and the patron would have worked closely to determine the layout of the text, paintings and their imagery, and decorated letters. The ruled lines formalized the layout of the text, illuminations, decorative borders, and embellished initials: “… in Parisian illuminated manuscripts of the early fifteenth century, the page ruling might affect not just the format of a miniature, but its internal spatial organization and objects represented, for instance the alignment of roof-lines or the doorposts of buildings [9].”
Pinpricks were made in the margins of the parchment to align the straight edge that would be used to draw the lines [10]. The same set of pinpricks were used to rule both sides of the page for perfectly aligned layouts of the recto and verso of the page. There is evidence of diluted organic red ink/watercolor ruled lines visible in these folios (fig. 3). Examples of the pinpricks were not observed during the treatment and may have been trimmed before the book was bound. The ruled lines could be made with a hard stylus which left a physical impression in the parchment or ruled in color using leadpoint (a drawing tool made from a lead wire), graphite, or diluted ink [11]. A diluted transparent, organic red ink was used to rule these folios (diagram 1). The lines are more apparent on the verso because they have not faded as badly as those on the recto. The careful execution of the ruling also helped to reduce visual disruption of either side of the translucent vellum. The lines of text are perfectly aligned on either side of that page (fig. 1).
FIGURE 3.
Detail of ruled lines in organic red ink taken from the verso of the St. Margaret folio. Photograph by Brook Prestowitz.
DIAGRAM 1.
A model of the ruled lines used in the folios.
Preliminary sketching would also have been drawn at this stage followed by an initial, light inking of forms. Artists used hardpoints made of metal or bone to incise a line that did not leave behind a colored mark on the parchment to sketch out a design in a manuscript [12]. Leadpoint, graphite, and dilute ink were also used for sketching designs [13]. Evidence of preliminary sketches is not seen in the main paintings when looking through the verso. This may indicate that the artist chose to use hardpoint for preliminary sketches so that it would not be apparent from the reverse side of the folio.
However, there is possible evidence that a dull yellow-green organic paint was used for underdrawings of the decorative borders. One example is a set of leaves in the top right corner of the Pentecost border that has been left exposed rather than painted over with green or shell gold (fig. 4a, b). A similar kind of paint and style of line is seen peeking through areas of paint losses in the border flowers of all the folios in various places (fig 5 a, b). Even so, it is difficult to say with certainty that this is, in fact, underdrawing. The same color paint and style of line has also been applied as a glaze over the flowers to enhance their form. In fact, the paint of the pair of inked leaves runs over the blue paint in the acanthus leaf motif. It is also possible that the motifs were painted first, followed by the flowers.
FIGURE 4A.
Detail of unpainted leaves drawn in yellow-green media located at the right corner of the Pentecost folio, possibly indicating the use of underdrawing in the borders. Detail taken from a photograph by Matthew Hamilton.
FIGURE 4B.
Expanded detail of the unpainted leaves in the top right corner of the Pentecost folio. Detail taken from a photograph by Matthew Hamilton.
FIGURE 5A.
Detail of dianthus flowers with the green leaf showing a yellow-green painted line revealed through the media loss. Photograph by Brook Prestowitz.
FIGURE 5B.
Another detail of a different dianthus leaf showing the yellow-green media possibly indicating use of underdrawing. Photograph by Brook Prestowitz.
Writing Media and the Scribe’s Work
The scribe would write the text before it was sent to the artisan who applied the gilding. Many manuscript illuminations depict artists and scribes at work, offering tools and methods used by scribes. Here, St. Mark is depicted writing his gospel using a board that is attached to his seat at an angle, he holds a quill pen, and the parchment rolls over the top edge of the writing board (fig. 6). There are two elements in the text: the rubric, written in a thick, red ink that looks more like paint than ink; and the plain text written in black iron gall ink, which has shifted to brown-black with age. It was common for one scribe to write the text and another scribe known as the rubricator to write the rubric (fig. 7) [14]. The script font used in the folios is generally referred to as littera textualis a form of blackletter or gothic script written in the bookhand form of lettering rather than document form of lettering. Littera textualis is marked by increased length and shortened width of the letters as well as use of a kind of shorthand to abbreviate common letter combinations for economy of space and cost [15].
Quill pens, made from the flight feathers of any bird, were used for writing and drawing in 15th century Europe. The size of the bird, like a goose (large quill) or crow (fine quill), directly impacts the size of the nib and therefore the width of the drawn line. A nib was formed by making a series of cuts in the quill using a pen knife. The most popular quills were made from goose feathers, and it was reported that geese from the coldest climates made the best pens [16]. Quill pens have a springy flexibility that creates lines that have varying widths in the same stroke. Another feature of the quill pen is that it can hold a small reservoir of ink, reducing the frequency that the scribe must recharge the pen and increasing the length of a single line that may be drawn with a quill pen. The reed pen by comparison is much more limited in flexibility and length of use after each charging of the pen with ink. These characteristics help to identify when a quill pen has been used to make a drawing.
Quill pens, made from the flight feathers of any bird, were used for writing and drawing in 15th century Europe. The size of the bird, like a goose (large quill) or crow (fine quill), directly impacts the size of the nib and therefore the width of the drawn line. A nib was formed by making a series of cuts in the quill using a pen knife. The most popular quills were made from goose feathers, and it was reported that geese from the coldest climates made the best pens [16]. Quill pens have a springy flexibility that creates lines that have varying widths in the same stroke. Another feature of the quill pen is that it can hold a small reservoir of ink, reducing the frequency that the scribe must recharge the pen and increasing the length of a single line that may be drawn with a quill pen. The reed pen by comparison is much more limited in flexibility and length of use after each charging of the pen with ink. These characteristics help to identify when a quill pen has been used to make a drawing.
FIGURE 6.
St. Mark writing his gospel using the tools of a medieval scribe. Detail taken from photograph by Matthew Hamilton.
FIGURE 7.
Comparison of the text written in iron gall ink and the rubricated text in thick, opaque red ink. Here the section is introduced and interspersed with ‘V’ for versus and ‘R’ for responsum and ‘Oracio’ at the end which directs the reader to pray. Detail taken from photograph by Matthew Hamilton.Detail taken from photograph by Matthew Hamilton.
Iron gall ink was used for the body of the text. This type of ink was used extensively in Europe by the 1100s and is a metallo-organic compound made from a reaction that combines ferrous sulfate (a pale green, iron compound), acidity from sources like vinegar, and tannins extracted from oak galls. A gum binder was added to the dye to increase viscosity, keeping it from bleeding into the paper, and to help it bind to the parchment or paper. The ink is a translucent blue-black color when freshly applied and is a permanent, bodiless dye (no visible pigment particles are present). The lack of pigment particles in the ink allows it to flow effortlessly from the pen, eliminating clogging issues which was likely a frequent problem for the rubricer who used a very thick, paint-like ink. Interestingly, a few areas of the text have been reinforced with a carbon black ink made of carbon particles suspended in a solution of water and a binder (fig 8). This is often a good indication of the degree of fading of iron gall ink because the carbon ink would have been a good match for the iron gall ink before it degraded.
FIGURE 8.
Detail of reinforced letter showing the difference in the faded iron gall ink (brown colored ink) and the carbon black ink used to reinforce the letter ‘e’ on the recto of the St. Margaret folio. Detail taken from photograph by Matthew Hamilton.
Another artisan known as the rubricator would receive the folios with the black inked text. The scribe would make very lightly inked, small initials next to text intended to be rubricked [17]. Red ink was most commonly used for rubricing, however, ultramarine blue was occasionally used in very elaborate and expensive manuscripts. The media used for the rubricing is more like a thick paint than an ink that was made of vermillion, a mercury-based pigment.
The rubric in the folios is written in red pigmented ink and was used to denote headings and provide instructions. The form used in a book of hours is descended from the rubric in a breviary which the clergymen would follow while conducting ceremonies. In a book of hours, the rubric oriented the reader to follow chants and prayers that emulated the clerical lifestyle. In this case study, the rubric introduces text like “Mémoire de Saint Sébastien” and indicates ‘V’ for versus (verse) and ‘R’ for responsum (response) and ‘Oracio’, Latin for pray (fig. 8) [18].
Gilding
Once the text was completed, the underdrawing set in during the formatting stage for the borders, paintings, and illuminated letters were usually reinforced with a dilute ink or paint. The folios would have remained loose as they were passed between the artists following the different steps in making a manuscript. It would be much easier to work on the folios in the unbound state and it would also increase efficiency as more than one scribe or illuminator could be working at the same time. Next, the folios were passed to an artisan who completed the relief gilding. This kind of gold application is different from shell gold, discussed later, which is used like a watercolor. Relief gilding has been used extensively in the illuminated folios, around the paintings like a frame, dotted throughout the decorative borders, and in the illuminated letters. Evidence of the chronology of manuscript production is present in an area where the gilder accommodated the dot of an ‘i’ that extended beyond the ruled text margin (fig. 9).
FIGURE 9.
The gilder accommodated part of the text of the St Mark folio revealing the order of manuscript production. Photograph by Brook Prestowitz.
Gold leaf was applied to a three-dimensional gesso ground. Gesso is a water-based mixture of a white pigment like chalk or gypsum, water, and glue or gelatin [19]. Often some amount of pigment was added to the gesso to enhance the color of the gold leaf. Red and yellow earths and gray were the most common colors used. Losses in the gold leaf have revealed that the gesso in the folios is a gray color. The leaf would be burnished with a polished agate burnisher after it was applied over the gesso in order to increase the brilliance of the gold. The burnished relief gilding has a beautiful metallic glisten that catches the light in different angles, drawing the viewer’s attention back to the manuscript.
Artist's Technique
After the gilding was completed, the folios would have been passed to the painters to complete the paintings, illuminated letters, and borders. One artist could complete all three of these components; or different artists who specialized in one aspect of the painting would have worked together to complete the decorations in a single manuscript [20]. The brush is the more obvious tool used for applying paints, however, the quill pen was also used to create elements of the paintings such as in the illuminated letters, scrolling lines or outlines, and underdrawings [21]. The white line in the illuminated letter (fig. 10) and the black line creating the bryony vine in the borders (fig. 11), were likely drawn with a quill pen. The width of the line remains consistent in a single stroke as well as in consecutive strokes throughout the folios which is indicative of a more structured drawing implement like the pen compared to the brush.
FIGURE 10.
Detail of the white lines applied with accuracy and consistency, likely by using a fine nibbed quill pen. Photograph by Brook Prestowitz.
FIGURE 11.
Detail of the black lines applied with accuracy and consistency, likely by using a fine nibbed quill pen. Photograph by Brook Prestowitz.
It was not until the 19th century that artists' materials were sold in the way that we are used to today. In the medieval era, artists, or their apprentices, would refine their own pigments and mix their own paints. By the fifteenth century, when these folios were made, artists were able to buy processed pigments from apothecaries or merchants relieving the artist from some of the labor involved in making paint [22]. A sensitivity to materials and an understanding of the chemistry needed to process them was essential to making good quality paints. To make a paint, the artist would first refine the source of the pigment by grinding. Then the ground pigment would be purified using various processes such as kneading ground pigment into wax and resin dough, cooking them for a specific time, or washing and levigating them multiple times. Organic colorants were extracted from the plant or animal source and sometimes cast onto a more translucent material to add bulk or opacity. Once the pigments and dyes were extracted, they were worked into a paste, first with water, then with a binder. Typically, a pigment is mulled with a stone or glass muller as the chosen binder is added gradually until a paste is formed (Slideshow 1). The purpose of mulling pigment is akin to kneading bread, in which the mixture is made into a homogeneous mixture.
A binder is a material, such as oil, acrylic, or eggwhite, that is added to pigments to create a cohesive paint film and adheres the pigment particles to themselves and to the support. The binders used for manuscript painting during the time these folios were made included glare made from egg whites and gums such as fruit tree gums and gum arabic. Other possible binders included animal or fish glues and egg yolk. Paints made with a proteinaceous binder like glare, yolk, or glues are water-based and form an insoluble paint film once dried. These paints are called tempera paints (egg-based protein binders) or distemper (glue, collagen-based protein binders).
Gum arabic became the preferred binder by the fifteenth century as it could be rewetted and used and it is still used today in watercolors [23]. Since the gum-based pigments could be re-solubilized, they could be made in batches and stored for later use in bladders or small vessels like shells, hence the name ‘shell gold’ for gold watercolor. Gum arabic formed a more flexible paint film than glare and resisted cracking and crumbling as it aged [24]. All these characteristics of gum arabic-based paints added to its appeal as a binder for paints used in illuminated manuscripts.
Illuminators would mix batches of colors and apply them systematically in large fields. This mechanized part of the creative process, increasing production rates [25]. The unfinished recto and verso of folio19 in the Book of Hours M. 358 in the Morgan Library & Museum collection offer a glimpse of the painting process. Folio 19 still has the artist’s underdrawings in the borders, the gilding that has not been outlined yet, and the initial application of general color application. The transmitted light image of the St Mark folio emphasizes the first application of paints in fields by reducing the visibility of the delicately layered modeling of forms (fig. 12). The density of the paint layers is also emphasized in this image.
Next, the layers of ‘underpaint’ were further refined with many, fine, long brush strokes of paint made in close parallels or cross hatching to create form and shadowing [26]. Fine stippling of the paint was also used to create tone and form. Another method to create depth was to apply transparent, glossy glazes of organic colorants over the opaque paints [27]. The artists’ choice to use transparent glazes rather than mixing varying degrees of black with colored pigments for shadow is interesting. Artists were not opposed to mixing lead white with other pigments to create tints used frequently in the sky, clothing, and skin tones. Was this technical decision influenced by style, behaviors of the paints, or economy of materials? Whatever the reason, the artist has skillfully used his materials and techniques to create form and shadow in the paintings (Slideshow 2). The final step in painting was to apply the outline to the figures and around the relief gilding to clean up any ragged edges. In these folios, the black carbon outlines are only applied around the relief gilding and to create the bryony vine in the borders.
Next, the layers of ‘underpaint’ were further refined with many, fine, long brush strokes of paint made in close parallels or cross hatching to create form and shadowing [26]. Fine stippling of the paint was also used to create tone and form. Another method to create depth was to apply transparent, glossy glazes of organic colorants over the opaque paints [27]. The artists’ choice to use transparent glazes rather than mixing varying degrees of black with colored pigments for shadow is interesting. Artists were not opposed to mixing lead white with other pigments to create tints used frequently in the sky, clothing, and skin tones. Was this technical decision influenced by style, behaviors of the paints, or economy of materials? Whatever the reason, the artist has skillfully used his materials and techniques to create form and shadow in the paintings (Slideshow 2). The final step in painting was to apply the outline to the figures and around the relief gilding to clean up any ragged edges. In these folios, the black carbon outlines are only applied around the relief gilding and to create the bryony vine in the borders.
FIGURE 12.
St. Mark folio in transmitted light showing the initial application of paint in general fields of color. Photograph by Brook Prestowitz.
The Pigments
A rather limited and consistent color palette was used and consisted of blue (possibly two types), green, opaque red, opaque yellow, black, brown, transparent red, and transparent yellow-green. The artist has very skillfully layered opaque and transparent colors or mixed colors with white to create tints, expanding the range of colors in each painting without adding more pigments to the palette. The paints used in the illuminations may be divided into opaque mineral-based pigments, transparent organic dye-based pigments, and metallic paints.Technical analysis of the folios was not completed during the treatment. It is possible, however, to estimate what pigments were used based on observation under ultraviolet (UV) fluorescence and magnification and comparing those observations to existing research on similar manuscripts.
Opaque Mineral Pigments
Lead white, a very dense, opaque, and toxic paint, was used ubiquitously by medieval painters because of its favorable working properties and color. Other types of white pigments available at the time the folios were painted, included bone white, chalk, whites made from egg or oyster shells, and gypsum. Indeed, gypsum has been identified in other manuscripts that have received technical examination of their pigments. Gypsum gesso was used by manuscript artists to prime areas for the paint layers [28]. Certain characteristics observed in the folios infer that the white pigment used in the paintings is lead white. When examined under UV light, areas of white paint fluoresce a pale pinkish white, a characteristic of lead white [29], that is also mottled with less fluorescent light gray. The fact that areas of the white paint had begun to turn gray, visible in normal light, was a telling indication that the paint was lead white, because it darkens when exposed to sulfurous air pollutants. The pinkish fluorescence and slight absorption of UV seen as gray, is related to the darkening of the pigment. Additionally, the white paint films were very brittle and prone to cracking, flaking and losses. Lead white is known to act as a drying agent in paints, a quality that has enhanced the desiccation and failure of paint films of lead white and tints of other pigments mixed with lead white when the binding medium is a protein or gum [30].
The most famous blue pigment of this time was ultramarine blue. Made from lapis lazuli mined in Afghanistan, this was the most expensive pigment and was second in cost only to gold [31]. Ultramarine was expensive because of its distant source, hence its name which translates to ‘beyond the sea’, and for the complex and unique processing method required to make the pigment. This blue was used for important biblical figures, particular the Virgin Mary, and symbolized royalty when used in imagery. Having this pigment in the artist's palette and the quantity that was used in the manuscript were excellent indications of the wealth and influence of a patron. Ultramarine loses its color when ground too finely, thus it is often quite granular, like sand. There also tends to be other mineral impurities in ultramarine, even in the most purified form. The blue paint in the folios is granular and impurities were observed in the paint under magnification. When examined with UV, the blue had a dark blue fluorescence, which is characteristic of ultramarine blue (fig. 13a, b) [32]. Another blue pigment that may have been used is azurite blue. However, there was not enough context to indicate if it was present.
FIGURE 13A.
Detail of St. Margaret in normal light. Detail taken from photograph by Matthew Hamilton.
FIGURE 13B.
Detail of St. Margaret in UV light exhibiting blue fluorescence of the blue paint. Detail taken from photograph by Matthew Hamilton.
Green mineral pigments commonly used when the folios were made include green earths, malachite, and verdigris, a synthetic color known since antiquity. Of course, there were many combinations of yellows and blues to make a green mixed paint. The green in the folios is a very fresh green that does not appear to be mixed with anything except a blue mineral pigment to achieve more of a blue-green color (fig. 14). The author estimates that the green used in the folios is malachite green. The pigment is very gritty, a characteristic of malachite paints because the pigment loses color intensity if ground too finely as Cennini expresses in his manual: ‘For the sake of the color, work it up very, very little, with a light touch; for if you were to grind it too much, it would come out a dingy and ashy color [33].’ Green earths are siliceous, dull, and soapy like clay and range in color. The green used in these paintings is a very fresh, bright, light green. The green paint absorbs UV except when it has been mixed with the blue pigment, estimated to be ultramarine, in which case the mixed green takes on a blueish fluorescence (fig. 15a, b).
FIGURE 14.
Detail of thistles in the top left corner of St. Margaret exhibiting the mixture of green and blue pigments in varying ratios to achieve a variety of green tones. The base of the thistle flower at the top right corner has the least amount of blue mixed into it and it is more of the malachite yellow green color. Detail taken from photograph by Matthew Hamilton.
FIGURE 15A.
St. Christopher in normal light. Detail taken from photograph by Matthew Hamilton.
FIGURE 15B.
St. Christopher in UV light. The blue pigment is fluorescing blue while the green is absorbing. Areas of blue mixed with green are showing a darker blue fluorescence, most notable in the robe of the child, which is more of a blue green. Detail taken from photograph by Matthew Hamilton.
Three types of red commonly used in illuminated manuscripts are red lead, vermilion, and red earth pigments. Red led is more of an orange than a red color and was known as minimum. This is where the term ‘miniature’ comes from because of the extensive use of minimum in illuminated manuscripts. Red earths have very fine particles creating a buttery texture that is a dull red color. There is a significant range in color of red earths from lighter, orange-red to an almost mauve color. Vermilion is made by grinding cinnabar, an ore mineral composed of mercury sulfide, the best quality of which was obtained from Spain [34]. The color of the pigment intensified the finer it was ground. By the medieval period, vermilion could be made synthetically making it more widely available. It is also known to have been popular amongst illuminators and rubricers. It is estimated that the red paint used in these folios is vermilion because of its’ brilliant red color, its dark purple blue fluorescence, and the manner in which it has been used (fig. 16a, b).
FIGURE 16A.
Rubriced text and red rose in the bottom right quadrant of St. Pope Urbane in normal light. Detail taken from photograph by Matthew Hamilton.
FIGURE 16B.
Rubriced text and red rose in the bottom right quadrant of St Pope Urbane exhibiting a dark purple fluorescence under UV. Photograph by Matthew Hamilton.Detail taken from photograph by Matthew Hamilton.
Other opaque pigments used in smaller quantities in the paintings are brown, black, and yellow. Opaque black pigments were made from carbon particles which have a very fine particulate size. Black was used to outline gilding, fine details, dark shadows in the paintings, and in the scrolling stem of the vine in the border. An opaque brown has been used in different architectural components and in modeling of forms to create shadow and depth. It is estimated that the brown is a type of earth pigment such as umber. Interestingly, there is a slight fluorescence in areas painted a light brown which is unexpected for an earth pigment (fig. 17a, b). The fluorescence is like that seen in the transparent, organic yellow pigment discussed below. Perhaps some of this organic yellow was mixed with the brown earth to achieve a certain hue.
FIGURE 17A.
Detail of St. Pope Urban in normal light. Detail taken from photograph by Matthew Hamilton.
FIGURE 17B.
Detail of St. Pope Urban in UV light exhibiting a yellow fluorescence in the light brown paint layers used in the vaulted ceiling, the shelf, and the baseboard on the right. Detail taken from photograph by Matthew Hamilton.
Finally, the artists have used a very small quantity of an opaque yellow pigment in the eyes and belly of St. Margaret’s dragon (fig.18a, b), in the marigold in the margin of the Pentecost folio, and the inside of the angel’s wings in the St. Matthew folio (fig 19a, b). Some yellows used in the medieval era were yellow ochre earth pigment, orpiment which is a sulfide of arsenic, lead-tin yellow, and Naples yellow, also a lead based pigment. The paint used in the illuminations absorbs UV as do all the yellows listed here. A particular favorite of the medieval artist was orpiment yellow, however, it had a reputation for being difficult to work with, reacting poorly when mixed with other pigments, especially verdigris and lead white [35]. In fact, artist manuals recommended mixing eggshell or oyster shell white with orpiment yellow to achieve tints of the yellow pigment. Orpiment also would react with the binding agent and cause degradation of the paint film within the artist’s lifespan.
FIGURE 18A.
Detail of the dragon in the St. Margaret folio in normal light. Detail taken from a photograph by Matthew Hamilton.
FIGURE 18B.
Detail of the dragon in the St Margaret folio in UV light showing absorbance of UV by the opaque yellow pigment. Detail taken from a photograph by Matthew Hamilton.
FIGURE 19A.
Detail of the angel in the St Matthew folio in normal light. Detail taken from a photograph by Matthew Hamilton.
FIGURE 19B.
Detail of the angel in the St Matthew folio in UV light showing absorbance of UV by the opaque yellow pigment. Detail taken from a photograph by Matthew Hamilton.
Transparent Organic Pigments
An organic red paint has been used in the leaves of the bryony vines in the gilded relief immediately bordering the paintings and in the illuminated letters. It was also used to decorate the more minor decorative letters, the brushed letters, and the bar spacers as well as the diluted ink for the ruled lines. It was possibly used as a mixture of lead white and other pigments to create pink or beige fields of color used in robes and skin tones. Organic pigments in illuminated manuscripts are often difficult to identify as destructive sampling is necessary. This is not recommended when the areas to sample are so small and any sampling may become an obvious loss or not provide enough material to analyze. Many different organic red dyes were available to the medieval artist including carmine extracted from the kermes scale insect, mainly the species Kermes vermilo which grows on the kermes oak; grain extracted from textile cutoffs already dyed with some organic red dye; Brazil wood, a dye taken from a series of tropical woods; and maddar from the Rubia tinctorum plant (a detailed discussion of these organic red pigments may be found in the
Art Conservator Vol. 15, No. 2 ). The very transparent organic dyes are cast onto a base to make a pigment with more body and opacity and that would allow it to be used as a paint. Two common bases were aluminum hydroxide made from alum, which made a more transparent paint, and calcium sulfate from chalk, which made a more opaque paint [36]. The molecular structure of organic pigments often makes them very fluorescent and sensitive to light damage. The areas in the paintings of the folios estimated to be organic red pigments have a strong pink fluorescence. Another organic pigment used in the folios is a yellow-green transparent pigment used in the flower stems, and as glazes over leaves painted in green and shell gold. This pigment has a dull yellow-green fluorescence in UV light seen in fig. 20a, b and fig. 21a, b. Potential organic yellows available to illuminators at the time included rhamnus yellow from the buckthorn berry, weld yellow made from the plant Resda, R. lutelo, saffron, or bile yellows from fish and other animal galls [37].
Art Conservator Vol. 15, No. 2 ). The very transparent organic dyes are cast onto a base to make a pigment with more body and opacity and that would allow it to be used as a paint. Two common bases were aluminum hydroxide made from alum, which made a more transparent paint, and calcium sulfate from chalk, which made a more opaque paint [36]. The molecular structure of organic pigments often makes them very fluorescent and sensitive to light damage. The areas in the paintings of the folios estimated to be organic red pigments have a strong pink fluorescence. Another organic pigment used in the folios is a yellow-green transparent pigment used in the flower stems, and as glazes over leaves painted in green and shell gold. This pigment has a dull yellow-green fluorescence in UV light seen in fig. 20a, b and fig. 21a, b. Potential organic yellows available to illuminators at the time included rhamnus yellow from the buckthorn berry, weld yellow made from the plant Resda, R. lutelo, saffron, or bile yellows from fish and other animal galls [37].
FIGURE 20A.
Normal light image of St. Ives. Detail taken from a photograph by Matthew Hamilton.
FIGURE 20B.
UV image of St. Ives, dark yellow-green fluorescence seen in the fore edge of the book St Ives’ hand and in the floor tiles. Detail taken from a photograph by Matthew Hamilton.
FIGURE 21A.
Normal light image of leaves in the top right corner of the Pentecost. Detail taken from a photograph by Matthew Hamilton.
FIGURE 22B.
UV image of leaves in the top right corner of the Pentecost. Detail taken from a photograph by Matthew Hamilton.
Metallic Paints
Shell gold has been used extensively in these folios. It was used heavily in the borders for the leaves of the flowers and in parts of the acanthus leaf motifs. The artist has also used it for the final outlining in the paintings rather than carbon black. Shell gold is made from gold leaf that is ground down and rinsed then combined with gum arabic to create a watercolor. Once dried, it could also be burnished like the relief gilding, but to a lesser degree. There is evidence of burnishing in the shell gold where it was applied as part of the acanthus motif (fig. 22).
FIGURE 22. The more yellow, reflective lines in the shell gold are the result of burnishing the pigment with an agate burnisher. Photograph by Brook Prestowitz.
FIGURE 23.
Transparent yellow-green paint applied over the shell gold to create shadow in the gold leaves. Photograph by Brook Prestowitz.
The shell gold has been enhanced to create details and shadow. The artist has used the transparent yellow-green paint to create shadow in the shell gold leaves of the flower (fig. 23). A similar effect is seen in the shell gold in the acanthus leaf motif that could be achieved in two different ways (fig. 24a, b). The artist may have used a transparent red paint as a glaze over the shell gold to create shadow. Another possibility is that the artist used a different type of metallic paint called mosaic gold, aurum musicum. This was made by heating sulfur and tin to make tin sulfide, a metallic reddish gold colored pigment that is less brilliant than shell gold. Viñas and Farrell argue that this is a rather rare pigment and that the way artists use mosaic gold inferred an approach to the paint as a separate color rather than as a cheap imitation of shell gold to be be used as an extender of or replacement for the precious, rare metal paint [38]. Further technical analysis would be necessary to confirm the identity of the pigment used as described.
FIGURE 24A.
An example of shell gold with a second pigment used to create shadow which may have been achieved by using a transparent organic red glaze over the gold or mosaic gold. Photograph by Brook Prestowitz.
FIGURE 24B.
An example of shell gold with a second pigment used to create shadow which may have been achieved by using a transparent organic red glaze over the gold or mosaic gold. Photograph by Brook Prestowitz.
A particular black paint that has a metallic sheen was noted in certain details when examining the works under magnification. The same paint was observed in details that would make sense to have a metallic appearance such as the key held by the pope, the iron bars on St. Margaret’s jail cell, the claws and teeth of St. Margaret’s beast, the clouds in several of the paintings, the arrowheads and fletches in the St. Sebastian folio (fig. 25), and the reflections of the rippling water crossed by St. Christopher. Perhaps shell silver was applied to these areas using the luster of the silver to articulate the reflectance of light off of smooth or metallic surfaces. The current black color makes sense because when silver is exposed to pollutants, it tarnishes and turns black.. Another curious factor was that these pigments were behaving similarly to iron gall ink (discussed in more detail in Part III) and sinking through to the opposite side of the parchment (fig 26a, b). It is possible that the paints used in these areas were shell silver, a combination of iron gall ink and shell silver, or something completely different.
FIGURE 25.
Detail of an arrowhead and a fletch in the St. Sebastian folio which have been painted with a metallic gray pigment. Photograph by Brook Prestowitz.
FIGURE 26A.
Detail of the key held by St. Pope Urban painted with a metallic gray black paint. Detail taken from photograph by Matthew Hamilton.
FIGURE 26B.
Detail of the key held by St.Pope Urban viewed from the verso, showing the paint sinking through to the verso of the parchment as it degrades. Detail taken from photograph by Matthew Hamilton.
cONCLUSION
The folios have been designed with great care. The patron paid to have only the best materials used by highly skilled artisans and painters to make their luxury book of hours. Five centuries later the artist's skill in designing the manuscript and rendering the paintings with heavy use of gold is still breathtaking. While much of this manuscript’s history remains a mystery, examination of the materials and techniques used by the artists in these eight folios has offered more insight into their history. Discussion of the treatment and preservation of the folios may be found in Part III: Condition and Preservation.
Acknowledgement
I would like to thank the owners of these beautiful works for giving me permission to share my findings and the answers to some of the questions I had as I examined and treated the folios. I am also grateful for the time donated by Dr. Joel Pattison to translate several of the folios.
Photography Credit | Brook Prestowitz, Matthew Hamilton, and Maggie Barkovic.
REFERENCES
[1] Jonathan J.G. Alexander, Medieval Illuminators and Their Methods of Work, (New Haven: Yale University Press, 1992), 22-23.
[2] Margaret Lawson, “Technical Observations: Materials, Techniques, and Conservation of the Belles Heures Manuscript” in The Art of Illumination: The Limbourg Brothers and the Belles Heures of Jean de Fance, Duc de Berry by Timothy B. Husband (New York: The Metropolitan Museum of Art, 2010), 325.
[3] Jonathan J.G. Alexander, Medieval Illuminators and Their Methods of Work, (New Haven: Yale University Press, 1992), 22.
[4] Ibid.
[5] Virginia Reinburg, French Book of Hours: Making an Archive of Prayer, c. 1400-1600, (Cambridge: Cambridge University Press, 2012), 22-23.
[6] Ibid, p. 22.
[7] Daniel V. Thompson, The Materials and Techniques of Medieval Painting, (New York: Dover Publications Inc., 1956), 24.
[8] Timothy B. Husband, The Art of Illumination: The Limbourg Brothers and the Belles Heures of Jean de France, Duc de Berry, (New York: The Metropolitan Museum of Art, 2010), 3.
[9] Jonathan J.G. Alexander, Medieval Illuminators and Their Methods of Work, (New Haven: Yale University Press, 1992), 40.
[10] Margaret Lawson, “Technical Observations: Materials, Techniques, and Conservation of the Belles Heures Manuscript” in The Art of Illumination: The Limbourg Brothers and the Belles Heures of Jean de France, Duc de Berry by Timothy B. Husband (New York: The Metropolitan Museum of Art, 2010), 329.
[11] Thea Burns, The Luminous Trace: Drawing and Writing in Metalpoint, (London: Archetype Publications Ltd., 2012), 66.
[12] Jonathan J.G. Alexander, Medieval Illuminators and Their Methods of Work, (New Haven: Yale University Press, 1992), 38.
[13] Thea Burns, The Luminous Trace: Drawing and Writing in Metalpoint, (London: Archetype Publications Ltd., 2012), 66.
[14] Margaret Lawson, “Technical Observations: Materials, Techniques, and Conservation of the Belles Heures Manuscript” in The Art of Illumination: The Limbourg Brothers and the Belles Heures of Jean de France, Duc de Berry by Timothy B. Husband (New York: The Metropolitan Museum of Art, 2010), 325.
[15] “2.5 The gothic Scripts-Textualis” School of Advanced Study University of London. https://port.sas.ac.uk/mod/book/view.php?id=891&chapterid=506 (accessed September 8, 2022).
[16] Joe Nickell, Pen Ink and Evidence: A study of Writing and Writing Materials for the Penman, collector, and document detective, (New Caste: Oak Knoll Press, 2003), 3.
[17] Margaret Lawson, “Technical Observations: Materials, Techniques, and Conservation of the Belles Heures Manuscript” in The Art of Illumination: The Limbourg Brothers and the Belles Heures of Jean de France, Duc de Berry by Timothy B. Husband (New York: The Metropolitan Museum of Art, 2010), 329.
[18] Joel Pattison, Assistant Professor of History, Williams College, personal communication.
[19]
[20] Margaret Lawson, “Technical Observations: Materials, Techniques, and Conservation of the Belles Heures Manuscript” in The Art of Illumination: The Limbourg Brothers and the Belles Heures of Jean de France, Duc de Berry by Timothy B. Husband (New York: The Metropolitan Museum of Art, 2010), 325.[25] Jonathan J.G. Alexander, Medieval Illuminators and Their Methods of Work, (New Haven: Yale University Press, 1992), 40-41.
[26] Margaret Lawson, “Technical Observations: Materials, Techniques, and Conservation of the Belles Heures Manuscript” in The Art of Illumination: The Limbourg Brothers and the Belles Heures of Jean de France, Duc de Berry by Timothy B. Husband (New York: The Metropolitan Museum of Art, 2010), 334.
[27] Paola Ricciardi, John K. Delaney, Michelle Facini, and Lisha Glinsman,” Use of Imaging Spectroscopy and in situ Analytical Methods for the Characterization of the Materials and Techniques of 15th Century Illuminated Manuscripts”, Journal of the American Institute for Conservation, 52: 1, 13-29.
[28] Salvador Muñoz Viñaz and Eugene F. Farrell, The Technical Analysis of Renaissance Illuminated Manuscripts from the Historical Library of the University of Valencia, (Cambridge: Harvard University Art Museums and the Universidad Politécnica de Valencia, 1999), 32.
[29] “Lead White”, Pigments Through The Ages, http://www.webexhibits.org/pigments/indiv/technical/leadwhite.html (Accessed October 23, 2022).
[30] Margaret Lawson, “Technical Observations: Materials, Techniques, and Conservation of the Belles Heures Manuscript” in The Art of Illumination: The Limbourg Brothers and the Belles Heures of Jean de France, Duc de Berry by Timothy B. Husband (New York: The Metropolitan Museum of Art, 2010), 336.
[31] Salvador Muñoz Viñaz and Eugene F. Farrell, The Technical Analysis of Renaissance Illuminated Manuscripts from the Historical Library of the University of Valencia, (Cambridge: Harvard University Art Museums and the Universidad Politécnica de Valencia, 1999), 32.
[32] “Ultramarine”, Pigments Through the Ages, http://www.webexhibits.org/pigments/indiv/technical/leadwhite.html (Accessed October 23, 2022).
[33] Daniel V. Thompson, The Craftsman’s Handbook “Il Libro dell’ Arte” Cennino d’Andrea Cennini”, translated by Daniel V. Thompson, (New York: Dover Publications Inc., 1960), 31.
[34] Daniel V. Thompson, The Materials and Techniques of Medieval Painting, (New York: Dover Publications Inc., 1956), 102-103.
[35] Ibid, p. 178.
[36] The Cloisters Museum & Gardens, ’When This You See, Remember Me,’ The Metropolitan Museum of Art (blog), https://blog.metmuseum.org/cloistersgardens/tag/forget-me-not/ (Accessed October 25, 2022).
[37] Daniel V. Thompson, The Materials and Techniques of Medieval Painting, (New York: Dover Publications Inc., 1956), 178, 186-187.
[38] Salvador Muñoz Viñaz and Eugene F. Farrell, The Technical Analysis of Renaissance Illuminated Manuscripts from the Historical Library of the University of Valencia, (Cambridge: Harvard University Art Museums and the Universidad Politécnica de Valencia, 1999), 26, 28.