Report to the Science and Art Department of the Committee of Council on Education on the action of light on water colours : presented to both Houses of Parliament by command of Her Majesty
An 1888 report to the British Science and Art Department, written by William James Russell and William de Wiveleslie Abney and printed for Parliament, measuring how light fades watercolour pigments over time. The four plates are rotated line graphs plotting fading against exposure, with numbered curves for each colour and a key listing pigment names beside them, offering a designer a sense of which hues hold up under light and which lose strength quickly.
