Les secrets du coloris : guide pratique d'observations expérimentales sur les harmonies coloriées faisant suite à l'édition de 1900
A 1904 French guide to color harmony by G. de Lescluze, published in Bruges by Librairie générale Demolin-Claeys for artists and students of color practice. Its single plate is a line engraving of three figures, rendered in a sketchy, heavily hatched style with the image shown sideways on the page. A designer might take its dense cross-hatching and diagonal shading as a model for tonal modelling in monochrome illustration.
