Quote Originally Posted by donbga
Ah, not exactly. Perhaps factory made products are subtractive but tri-color gum is additive.

Don Bryant

Don, then please explain to us how you get a yellow out of R and G pigments in a reflection print material.

Additive color theory says that this will not work.

In fact, additive color can only work with a transparency AFAIK. This is the only way to get black and white as well.