Non-colors (achromatic colors) are essentially black and white.
When mixing a color, these non-colors are only used to change the intensity and opacity of a color. It is best to avoid using too much of either black or white and rather try to rely on colors first and add them only at very last bit to get color for a final tweeking.
NON-COLORS for the decorative painter’s palette
W Titanium White, Zinc White
B Carbon Black, Lamp Black
TB Titan Buff (has a slight earthy tonality off white)
White is an invaluable color in the decorative painter’s palette. We use primarily titanium white because it is more opaque than zinc white. If there is an option between 2 similar colors, I always choose the one that is more opaque.
Best Uses: White is probably the most used color for most techniques except wood graining, where transparency is very important. However, an exception to that would be a cerused wood where white is used to finish the wood.
Technically a color, but it’s very close to white, so I place it in the non-color category. Next to white, titan buff is also a big favorite to mix a color or put on a palette.
Best Uses: Great for fissures and white veins for faux marble.
Black has a very valuable use, but is not heavily used. It’s primary use is for increasing the intensity of a color. When mixing colors, black is used at the end sparingly, otherwise, it tends to mud up colors. Expert colorists might disagree but this is the from decorative painter’s perspective and not from the easel painter.
We use carbon black because it is more opaque than mars black. Carbon black is the closest to ivory black which is no longer produced. Ivory black was made by burning ivory tusks and crushing the carbon which gave a very saturate and rich black. Mars is a synthetic black.
Best Uses: Used sparingly to mix colors. Best as a color on your palette when creating wood graining or other dark glazes like shagreen.
GREY – not a non-color
Contrary to popular thinking, the best grey is a combination of blue, brown, and white and not black and white. This is why it is not considered a non-color by the standards of the decorative painter.