Direct dyestuffs
A trade sample booklet from Sandoz, a Basel dye manufacturer, issued around 1900 for dyers and textile buyers. Its pictures are rows of small woven fabric swatches, each dyed at graded percentages, so they show how colour deepens from pale yellow and orange through red to near black as dye strength rises. A designer could take from them a ready reference for building a tonal ramp of warm colours, with each strip labelled by its dye concentration.
