What would a medieval king’s prayer book look like? If you search the collections of the V&A you can find a manuscript page which was originally part of the Book of Hours of Louis XII, king of France between 1498 and 1515. This Book of Hours, a type of devotional prayer book popular in medieval Europe, was illuminated by Jean Bourdichon, who at the time was official painter to the French Court.
This page shows the Nativity (Figure 1): baby Jesus is in a manger, surrounded by Mary and St Joseph, and of course, completing the scene as you would expect according to popular tradition, there are also an ox, a donkey and a group of shepherds peeping in through a window.
This is a beautiful miniature, and we want to keep it that way so that it may be enjoyed by our visitors for as long as possible. For this reason it was examined in detail by the V&A’s own conservation scientists: using sophisticated, non-destructive scientific techniques, we can find out if the miniature contains any materials which are particularly sensitive and prone to deterioration.
We identified a number of traditional materials, such as shell gold (a paint made with powdered gold, see Figure 2), the red pigments vermilion, hematite and red lead, the blue pigments azurite, indigo and lapis lazuli, the yellow pigments goethite and lead tin yellow type I, the white pigments lead white, calcite and gypsum, and the black pigment carbon black. These materials were often used mixed with each other (Figure 3).
Other, more unusual materials were also spotted: for example pyrite and mosaic gold and, most importantly, metallic bismuth.
The presence of bismuth was a real surprise: it was found in many of the grey areas (for examples in the donkey and the shepherds’ faces, Figure 4), but also used as an underdrawing, which is the ‘pencil’ sketch Bourdichon drew on the vellum before colouring in with his pigments. Under the microscope, the particles of bismuth look beautiful, with a metallic and iridescent sheen, which makes this material very special and unusual (Figure 5). It is only recently that bismuth has been recognised and documented as a painting material in its own right, by scientists at the National Gallery, London, the Getty Conservation Institute, Los Angeles, and by us here at the V&A.
“Spectroscopic investigation of Bourdichon miniatures: masterpieces of light and colour” (L. Burgio, R.J.H. Clark, R.R Hark, M.S. Rumsey and C. Zannini) in Applied Spectroscopy vol. 63, no 6, pp. 12-21 (2009).
“Investigation of the Painting Materials and Techniques of the Late-15th Century Illuminator Jean Bourdichon” (K. Trentelman, N. Turner) in Journal of Raman Spectroscopy, vol. 40, pp. 577-584 (2009).
“’Black Earths’: A Study of Unusual Black and Dark Grey Pigments used by Artists in the Sixteenth Century” (M. Spring, R. Grout and R. White) in National Gallery Technical Bulletin vol. 24, pp. 96-114 (2003).