They associated colour with commercial images, and viewed it as somehow contrary to the artistic identity of the etching.
Henri Guérard was one of the first artists to break the impasse with his colour etchings, which he showed at a number of exhibitions.
There were two ways to print an etching in colour.
For his café scene in Les Ambassadeurs, for instance, Henri Evenepoel applied the different inks to a single etching plate – the à la poupée method, which took great skill to prevent the colours from running into one another.
The other option was to print the colours separately, using a different plate for each one. The challenge then was to align or ‘register’ the separate plates correctly.
Gabriel Mourey, ‘Coloured Etchings in France’, The Studio 22 (februari 1901), nr. 95, p. 3-14 en 94-103
Phillip Dennis Cate, Marianne Grivel, From Pissarro to Picasso. Color Etching in France. Works from the Bibliothèque nationale and the Zimmerli Art Museum, New Brunswick/Paris 1992
Catherine Méneux, ‘Les Salons en Noir et Blanc (1876–1892)’, Histoire de l’art 52 (June 2003), p. 29–44