“Item: If thou like to temper a black paint for designing or painting. Take soft soot that grows on a cauldron or smoke hole [chimney], or other soot that is soft and good, and grind it.” Codex Germanicus 1. 1454-1463. Hamburg, Staats-und Universitätsbibliothek: fol. 73r. Transcription in: Heiles. 2018. Die Farb- und Tintenrezepte des Cod. germ. 1: p. 13-61.