Question

We have postulated an RGB model for the material properties of surfaces. Give an argument for using a subtractive color model instead.

Answer 1

When we want to work with reflected light, we employ the opposing subtractive primaries of cyan, magenta, and yellow.

In the visible spectrum, cyan is directly opposed to red; magenta is the opposite of green; and yellow is the opposite of blue. When cyan, magenta, and yellow pigments are laid upon a white, reflective substrate, each completely absorbs – or subtracts – its opposing counterpart from the white light. Printing processes use cyan, magenta, and yellow inks to control the amount of red, green, and blue light that is reflected from white paper.

Differences:

Subtractive	Additive
Subtractive (multiplicative) color mixing is not mixing of color ‘irritants’, but creating color by subtraction.	Additive color mixing occurs with the simultaneous action of various color sensations – ‘irritants’ on the eye.
The color display is obtained by filtering out the primary light color from white complex light.	The color display is obtained by the different light intensity of the primary colors: red, green and blue.
This system is used for works intended for printers	This system is used for works intended for monitor display