The term print (or pigment) primaries refers to the fact that these complements to the light primaries are the colored inks used to mix all possible print ink pigments.

In the preparing process of the red spray print ink, we did a large number experiments by the contrast and the orthogonal means, and then selected the quite good formulation.

Nostalgia for ink on paper and the rustle of pages aside, there's plenty of incentive to ditch print.