I read an interesting article today about color. Specifically about color and paint, but it can easily be extrapolated to ink. It was written by Sarah Sands at Golden Artist Colors and appears in the new issue of Just Paint, a newsletter produced by the staff at Golden.
I would recommend it to any artist, but I wanted to summarize a few of the major points here, with some observations of my own that may be particularly relevant to the topic in relation to printmaking.

While we tend to think of ink as having an intrinsic color, it is important to remember that it is actually a volume of pigment particles suspended in a medium (plate oil or perhaps an acrylic emulsion). The size, shape and quantity of these particles determine some of the secondary color properties that have a significant impact on the performance of an ink. These secondary color properties include:

  • Mass tone – Mass tone is the dominant color we see when the there is a thick layer of the ink present.
  • Undertone – Undertone colors emerge when the layer of ink is thin, the pigment load goes down (as when mixed with a large volume of transparent base) or it mixed with white.
  • Transparency – You can think of transparency (or opacity, which is its opposite) as the degree of hiding power that an ink possesses. But it is more than this as it also determines the luminosity of a color.
  • Tinting Strength – This characteristic affects how an ink behaves in a mixture. Does it take a little or a lot to move the color of a mixture?

Besides the intrinsic characteristics, there are other factors that impact the perceived color (and perception is the only thing that matters).
These include pigment load (which may be altered as we modify the body characteristics of the ink), film thickness (partially a function of process – lithography tends to deposit a thinner layer than relief, partially a function of tack – tackier inks tend to lay down a thicker layer) and sheen (affected by the absorbency of the paper or the stacking of ink layers).

For most artists (myself included) the process of mixing and choosing colors tends to be quite intuitive. Yet it is clear, that like most of our processes a better understanding of the physical processes involved will give us a firmer control of the medium. This is not to suggest that we will have complete control, there are too many variables at work for that to occur. But we may find that we have fewer frustrating days.