Why do printers have CMYK ink instead of RYB & black ink?

Question

Why do printers have CMYK ink instead of RYB & black ink?

In: 2442

Answer 1

We are essentially using *light* blue instead of blue and *light* red intead of red because when you combine dyes, **the color can only get darker.** So we use lighter variants of those “primary” colors we were taught in grade school so we can capture more of those lighter colors when printing [(which will STILL fall short of the RGB gamut)](https://upload.wikimedia.org/wikipedia/commons/1/1b/RGB_and_CMYK_comparison.png).

Not only do the dyes only get darker, but the lightness is also limited by how bright white a sheet of paper can be. Even the brightest sheet falls far short of the bright light RGB we stare into on our screens.