Color and Curious Creatures: Fifteenth-Century Block Books at the Morgan

Figure 1: Ars Moriendi, Germany, Rhine District, ca. 1465–1470, PML 3

Figure 2: Biblia Pauperum, Netherlands, ca. 1470, PML 1.2

Figure 3: Apocalypsis Sancti Johannis, Germany, ca. 1470, PML 8, fol. 43v

The Morgan owns the largest collection of block books in North America and they were some of J.P. Morgan’s earliest acquisitions. These are books in which both the images and the text are carved from a single woodblock, hence the term block book. The majority of these books were produced in Germany and the Netherlands in the mid to late fifteenth century, a transitional period in book printing history. The most common block books at the Morgan follow in a tradition of medieval manuscripts, and include multiple copies of Ars Moriendi (the Art of Dying),1 Biblia Pauperum (Bible of the Poor)2 and the Apocalypsis Sancti Johannis.3 Demons, angels, and biblical figures and scenes make up the lively images contained in these books which served to help the literate teach others. These books can be considered the graphic novels of their time.

Some of the Morgan’s block books are elaborately hand-colored on every plate, while others have little or no color. When colored, they tend to have a limited color palette including orange, red, green, yellow, and black, with few examples of blue and purple, and yet these colors are enough give life to the figures and creatures.

Figure 4: Canticum canticorum, 1465, raking light view of embossed versos, PML 21990

All the Morgan’s block books were printed on high quality white paper and nearly all of on folded sheets of Chancery size paper (approx. 12 x 17 1/2 inches (31.5 x 23 cm). The text and images were printed in brown or black ink on only one side of the sheet of paper. The versos of the sheets were intentionally left blank as the paper was strongly embossed by the pressure needed to print the wood block. This uneven surface made the versos unusable for printing. (figure 4). The carved woodblocks were saved for many years, and printed in small editions or "on demand". It appears that nearly every time a set of woodblocks was used to create a block book, the paper stock, printing ink, colors and format were chosen anew, and so each book is unique.

Figure 5: Sample map of Apocalypsis Sancti Johannis, PML 7, fols. 64v–65r, multiple tests made to identify ink and thirteen different colors

A collaborative study began in 2019, undertaken with Associate Curator of Printed Books, John McQuillen and Federica Pozzi and Elena Basso, Research Associates of the Network Initiative for Conservation Science.4 We wanted a better understanding of the materials used in this transitional period in book printing. For many years, block books have been considered anomalies in the world of printed books. In the mid fifteenth century manuscript illumination was waning and the use of moveable type was spreading. Using all the technical equipment available through this partnership, Pozzi and Basso took over 250 readings with a range of non-invasive techniques and removed twenty-four micro-samples for analysis from thirteen books so we could identify and categorize the multitude of colors and inks present. It was necessary to use a combination of techniques to build an accurate picture of the colors we saw.5

Scientific analysis of the color palette used in the Morgan’s block books has revealed the use of both mineral pigments and organic dyes, often combined in complex mixtures. The pigments discussed here were all known and available in the fifteenth century, most in use since ancient times. They tend to be inexpensive colors, with formulations that follow the traditions of medieval illumination, but are applied with less finesse and precision than we see in great manuscript illuminations.

Here is a brief discussion of some of the colors identified.

Figure 6: Flames made of red lead inside the mouth of hell in PML 8


Figure 7: Mineral form of red lead (minium) credit to By Rob Lavinsky, – CC-BY-SA-3.0, CC BY-SA 3.0

Figure 8: Orange in halo made by mixing lead tin-yellow with vermillion in PML 5

Orange, made from red lead, was present in nearly all the block books. Red lead is dense and granular and has strong covering power. It is often seen in the fires of hell or angels wings. It has been in use since the fifth century BC and is made by roasting lead white. We also found some examples of orange, made of red lead mixed with a small amount of vermilion or red ochre. In only one case (figure 8), in the stripes of the halo, do we see an orange made of a mixture of lead tin-yellow with vermilion. All these pigments were known in this period and are seen in manuscript illumination of earlier periods.


Figure 9: Buckthorn-yellow dye seen in landscape of PML 1.2

Figure 10: Unidentified organic yellow halo in PML 8


Figure 11: Buckthorn dye mixtures on paper from CAMEO

Figure 12: Buckthorn dye in powdered state


Most block book yellows are made of organic dyes. The dyes are thin and translucent, easily allowing the printing ink to show through the wash. There were many yellow dyes at this time, made from common plants including saffron, safflower, turmeric, saw-wort, weld and buckthorn. They were used on fabrics, as well as paper and parchment. It is often difficult to identify organics but with some micro-sampling and laborious liquid chromatography, scientists Pozzi and Basso identified Buckthorn (Persian berries) in several samples6 (figures 9, 11, 12). Mixing of dyes with pigments was common in manuscript illumination, and we found similar mixtures in the Morgan’s block books. All yellow dyes are sensitive to light and will fade with exposure, so it can often be hard to determine the original color, as faded yellow often looks like pale brown (figure 10).


Figure 13: Figure in a blue robe in PML 5, fol. 48

Figure 14: Detail of blue robe showing coarsely ground azurite with smalt

Figure 15: Ground azurite pigment

Blues are rarely present in our block books. All were found to be azurite7 based. Although not as expensive as ultramarine, azurite was more costly than most earth pigments and dyes which probably explains why so few examples are seen. Azurite is made from grinding up the mineral which contains many different forms of copper. Larger pigment particles make a darker blue. Particularly interesting was the discovery of a mixture of azurite and smalt8 in PML 5 (figures 13, 14). Scientific analysis showed traces of the elements Cobalt and Bismuth in this sample, which indicate smalt produced in Central Europe (Saxony and Germany).


Figure 16: Detail of vermilion used to accent an initial printed in black ink in PML 4

Figure 17: Ground vermilion pigment

Figure 20: Brazilwood dye in powder form

Figure 18: Brazilwood dye used to make a robe red in PML 8

Figure 19: Faded brazilwood dye on lion in PML 3–12

There are many varied red tones in the block books, but they do fall into clear groups. Some are pure vermilion, but most common are mixtures of vermilion9 with some red lead. These reds are generally somewhat opaque, although they may be applied in a thin layer. (Firgures 16, 17) We also identified the organic dye, Brazilwood10 in several locations. This light sensitive dye was used alone to make a moderately transparent wash, or mixed with other pigments and dyes to make darker and richer reds. (figure 18) One brown-colored lion was proved to be Brazilwood that had faded with long exposure to light (figure 19).


Figure 21: Red-purple robe in PML 5

Figure 22: Blue-purple robe in PML 5

Figure 23: Orchil purple robe in PML 5


Figure 24: Kermes, insects and powdered dye

Figure 25: Orchil dye on wool with dried lichen the source of the dye


Carmine11 also known as kermes, (figures 21, 24) is an organic dye made from insects. It was identified in a very few places, as it was rare and expensive. In PML 5, it was used to make two different purple colors. In one red-purple robe, (figure 21) carmine appears to be the main constituent but is mixed with small amounts of fine azurite; in the second example, a thick, powdery layer of azurite was applied on top of the carmine to produce a blue-purple robe. (figure 22) The third purple in PML 5, (figures 23, 25) a red-violet color, was identified as pure orchil12 a lichen-based dye which was frequently used on fabrics. It is unusual to see three purple variants with three different formulations and techniques of application on the same page, yet all of these dyes and pigments were known and used in the fifteenth century.


Figure 26: Copper green or mixture of azurite and organic yellow in tree in PML 6, fol. 37

Figure 27: Layering of blue over yellow in the wings of an angel in PML 7, fol. 32v

Greens were difficult to identify precisely with non-invasive techniques. Nearly all contain a copper-based pigment, which could be a copper green or copper blue,13 both of which were mixed with yellow. Based on XRF data, visual examination, and on the lack of corrosion of the paper, we believe that most greens are mixtures of azurite with an organic yellow (figure 26). In many places the two colors are thoroughly mixed before application to the paper, but in the angels’ wings in PML 7 (figure 27) we can clearly see that azurite blue and possibly a malachite green were mixed and applied over a yellow organic base.

As noted earlier, all the pigments discussed were known and available in the fifteenth century. Identification of these colors through close looking and scientific analysis and their consistent use in many different blockbooks, indicates that the books were colored contemporaneously with printing.


The next installment will discuss the problematic pigments found in some block books.

End notes

  1. Ars Moriendi, see CORSAIR records for PML 3, PML 4, PML 273, PML 274, PML 20583
  2. Biblia Pauperum, see CORSAIR records for PML 1.1 and PML 1.2, PML 2, PML 3193, PML 19328
  3. Apocalypsis Sancti Johannis, see CORSAIR records for PML 5, PML 6, PML 7, PML 8, PML 1051, PML 21786
  4. Federica Pozzi, Associate Research Scientist and Elena Basso, Research Associate in the Dept. of Conservation and Scientific Research, The Metropolitan Museum of Art, New York, N.Y.
  5. Non-invasive tools included XRF and Raman spectroscopy for inorganic pigments (earth pigments, often containing metals like iron, lead, copper) and FORS (Fiber Optic Reflectance Spectroscopy) for organic materials, like plant-based dyes. Micro-samples of some pigments and inks allowed us to do SERS (Surface Enhanced Raman Spectroscopy), and HPLC (High-Performance Liquid Chromatography) as well as SEM/EDS (Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy).
  6. Persian berries, also called buckthorn berries, are small berries from any shrub of the buckthorn family. A water-soluble dye was extracted from the berries for use in textiles, wood stains and lake pigments and can vary in color from yellow to green. Buckthorn berries - CAMEO
  7. Azurite
  8. Smalt
  9. Vermilion, a bright-red pigment composed of synthetically prepared red mercuric sulfide. Known in Europe since the eigth century, strong covering power, same as cinnabar, natural mineral form.
  10. Brazillwood
  11. Carmine Kermes, a natural red dye obtained from the dried bodies of the female insects, Kermes vermilio planchon and Kermes ilicis (formerly Coccus ilicis), found in southern Europe on the small evergreen Kermes oak, Quercus coccifera, Kermes dye, used since ancient times.
  12. Orchil orcein
  13. Malachite verdigris information at Pigments through the Ages - Overview - Verdigris

Reba F. Snyder
Paper Conservator
Thaw Conservation Center
The Morgan Library & Museum

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Thaw Conservation Center

The Thaw Conservation Center at The Morgan Library & Museum, a world-class laboratory for the conservation of works on paper and parchment—drawings, prints, photographs, illuminated manuscripts, rare books, fine bindings, and literary, historical, and music manuscripts—as well as a place for conservation studies, opened in February 2002.
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