Color for Paper

Chris Dannen, writing for Fast Company, has the story behind iPad app Paper’s innovative color mixing feature:

What vaulted FiftyThree over a hot pile of math was a major insight gleaned from two dead German scientists named Paul Kubelka and Franz Munk. In 1931, they published a paper called Ein Beitrag zur Optik der Farbanstriche, or “a contribution to the optics of paints,” which showed that this color-space question predated computing by several decades. The paper laid out a “theory of reflectance” with an equation which could model color blending on the physical experience you have with the naked eye. That is, how light is reflected or absorbed by various colors.

[…]

Moving from a three-dimensional color-space to six dimensions was the difference between old drab color-mixing and absolute realism. “What creates the shades you see between paints is this interplay of absorption and reflection,” says Petschnigg. “Compare red nail polish to red ink: both are red, but the nail polish will be visible on black paper because it reflects light. The ink won’t be, because it absorbs light.”

Details matter.