“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.