Pseudo-isochromatische Tafeln für die Prüfung des Farbensinnes
A German medical atlas of 1889 by the ophthalmologist Jakob Stilling, published in Leipzig, containing pseudo-isochromatic test plates for examining colour vision. The three plates show a field of irregular mottled blobs in browns, greens and yellows, with a hidden figure picked out in red or pink dots that stands out only to viewers with normal colour perception. A designer might take from them the idea of camouflage-like pattern built from varied organic shapes, and how a figure can emerge from a field of near-matching hues.
