Black copper vitreous pigment

Black copper vitreous pigment (Schwartz kupffer lot) Fig. 42 (missing IMG) Quote 22

In the fifteenth century close collaborations existed between different crafts. Glass painters for instance, adopted techniques from oil painting and the graphic arts, transforming the medieval craft to a high level of artistic excellence.[2]<p>[118] Scholz, 2001, 'Monumental Stained Glass in Southern Germany in the Age of Dürer', p. 17.</p>,[3]<p>[119] Bol, 2013, <em>Seeing Through the Paint.</em></p>,[4]<p>[120] Straub, 1984, <em>Tafel- und Tüchleinmalerei Des Mittelalters.</em></p> Glass-painter workshops in Strasbourg were innovative by introducing new graphic elements, and worked from templates by Rogier van der Weyden and Martin Schongauer. Around 1500, designs by Albrecht Duerer, Hans Baldung Grien and others were executed in glass. This mutual exchange is reflected also in contemporaneous sources on black pigments. In his treatise, Boltz von Ruffach included a black pigment that was prepared by painters of glass (see citation). This pigment is called schwartz kupffer lot and was utilized as black vitreous paint to draw linear contours on glass. According to Ruffach, as a watercolor this pigment is of a falb brun (brownish) color and is as easy to use as the black of soot.[5]<p>[121] Boltz von Ruffach, 1549, <em>Illuminier Buoch</em>, p. 96-97. https://doi.org/10.3931/e-rara-5578.</p> Such a glass paint is already recorded in the fifteenth-century Montpellier Liber diversarum arcium. [6]<p>[122] Clarke, 2011, <em>The Medieval Painter’s Materials and Techniques: The Montpellier Liber Diversarum Arcium.</em></p> It is prepared in a similar way to the one Ruffach describes, just by mixing 1 part pulverized black copper(II)oxide (CuO, crocus veneris, generated by repeated annealing of thin copper sheets and subsequent washing and grinding), 3 parts of pulverized dark blue glass, 4 parts of forged iron particles (ger: Hammerschlag) and a bit of manganese. Due to the use of blue glass, this recipe results in a blue-black pigment. To prepare a watercolor, the black pigment was tempered with gum water. It is reasonable to imagine that Burgundian illuminators knew about vitreous paints, but how far they applied these pigments for their own work requires further research.

[1] “To prepare black kupferlot from kupferlot. Take one lot of pure Hammerschlag (residual iron particles after forging), and one lot of kupfferäschen (copper ash, pulverized black copper (II) oxide, crocus veneris), two lot of Schmelzglas (ground glass). Grind it all together, until it has no sandy smoke [?], but you should grind it on a copper plate, temper it with gum water, with this you can shade all light colors, but especially white color.” In: Benzinger. After 1549. Illuminier Buch Künstlich Alle Farben Zumachen, handwritten copy of Boltz von Ruffach. 1549. Illuminier Buoch), GNM Nürnberg, Ms 32075: fol. 34r. https://digilib.mpiwg-berlin.mpg.de/digitallibrary/jquery/digilib.html?fn=/experimental/ARB/ARB_PRIMARY_SOURCES/ARB_manuscripts/MS_580/pageimg.
[2] Scholz. 2001. Monumental Stained Glass in Southern Germany in the Age of Dürer: p. 17.
[3] Bol. 2013. Seeing Through the Paint.
[4] Straub. 1984. Tafel- und Tüchleinmalerei Des Mittelalters.
[5] Boltz von Ruffach. 1549. Illuminier Buoch: p. 96-97. https://doi.org/10.3931/e-rara-5578.
[6] Clarke. 2011. The Medieval Painter’s Materials and Techniques: The Montpellier Liber Diversarum Arcium.