"The effect of layering is so powerful that it has transcended its roots in painting with oils and is now in­corporated into all professional digital illustrati

"The effect of layering is so powerful that it has transcended its roots in painting with oils and is now in­corporated into all professional digital illustration tools. If you use Photoshop, or Illustrator, or any other computer graphics tools, you'll be making images in layers." The layering described there, is more about what blend modes are for, layering can also be quite dumb by itself. The roots of DTP software layers lie pretty much all in the necessities of print, not painting, where you have to have a layer per color anyway. Wondering why the article stops short of the point, why (digital) reproduction of paintings is a lossy process in general, and especially for archiving. Total Appearance Capture systems exist but are rarely applied to paintings. A 2D-RGB raster can only represent the appearance of a light reflective object from a single angle und very specific ambient conditions. How a painting interacts with light in a room is a complex process of all kinds of optical phenomena (reflection, absorbtion, diffraction, refraction ...) as described in the arcticle.