Benzo Colours on Cotton Yarn, Part I
A dye sample book issued in 1921 by Farbenfabriken vorm. Friedrich Bayer & Co. of Leverkusen near Cologne, made for textile dyers and mill buyers testing Benzo direct colours on cotton yarn. Each page ruled with a printed frame holds two columns of dyed yarn swatches beside German trade names, numbers and concentration figures, giving graded blues, violets and blacks as ready-made palettes.
