Something that’s black absorbs all the light of any color that hits it. Regular pigments absorb some colors well but not others- the color you see comes from the light they don’t absorb.So you want to mix some different color pigments- say red and blue- to try to absorb as big a range of colors as possible. You may also want to use some dark green or yellow other different pigment to adjust the color if you get something brownish or purplish. You want to use the darkest starting pigments possible, because you need to get all the light absorbed before it has a chance to bounce back out of the surface.
It’s pretty hard to get a good black by mixing regular colored pigments, because these are chosen to absorb very little of some colors of light. That’s why ink-jet printers usually use separate black ink, with pigments that absorb a broad spectrum of colors, rather than a mixture of the colored inks.
Adam, Mike and Tom
(published on 10/22/2007)
