Das Färben des Papiers auf der Papiermaschine
A German technical manual by Emil Heuser, published in Berlin in 1913 by C. Hofmann, on dyeing paper while it runs on the papermaking machine, aimed at papermakers and mill engineers. The pictures are line-drawn machine schematics: rollers, tanks, dye troughs and feed pipes drawn in plan and side elevation with lettered parts. A designer could borrow their clean, labelled mechanical diagram style for industrial or process graphics.
