In painting with oil, it’s standard to use white to lighten mixtures. White (whether lead white, titanium white, or zinc white) is incredibly useful as there are many colors that can’t be obtained without it. Contrariwise, there are also colors that can’t be mixed if you use white. White lightens, but it also cools (in most circumstances), decreases chroma (except when applied in small amounts with some cool colors), and increases opacity. There are some circumstances in which you want to lighten (increase the color’s value) without the other effects of adding white. For example:

• In traditional oil painting technique, it is often appropriate to keep shadows transparent. That basically means mixing shadow colors without any white.
• Because white usually decreases chroma, mixtures involving white can be lower in chroma than you want. As a result, painters sometimes complain of paint mixtures that are too “chalky.” They get lights that have a pastel look with low chroma. While that is sometimes exactly the right color (in which case no one complains) we sometimes want lights that are as high in chroma as possible.

While oil painters don’t generally depend on white-freen paint mixtures to nearly the degree that watercolor painters do, it’s important to know how to paint without white when you need to. If you just need a dark color, that’s easy. If you need to paint a range of values, then you’ll need to find mixtures that achieve that value range. The ease of doing so depends on what part of the color wheel you’re working with.

There are plenty of high-value yellows, for example. If you need to lighten a yellow or brown mixture, you can usually do so by mixing in a lighter yellow (I like lead-tin yellow for this purpose, or a cadmium yellow if I’m looking for higher chroma). Reds are more difficult—it’s hard to mix a light red without dropping the chroma (i.e., making it pink). Genuine vermillion is sometimes useful because it is somewhat light and doesn’t drop chroma in mixtures the way cadmiums of similar color can do. Oranges can be lightened by adding a lighter yellow and then, if necessary, adjusting back to the right hue with a bit of red. A yellow green can similarly be lightened with yellow.

Cooler colors (blue, green, blue-green, purple) are more difficult to lighten, since the tube colors in this range are often pretty dark. Some cobalt blues can be relatively light and therefore quite valuable (although they are also opaque, so they don’t help as much if you are looking for transparency).

The other solution, of course, is to paint thinly onto a white surface, just as in traditional watercolor. The method used by Ted Seth Jacobs and his students such as Tony Ryder, for example, typically begins with a “color wash.” That means applying the first layer of paint very thinly, mixed with dilutant. While wet, the color can be lightened by wiping away paint with a dry rag or brush; or one dipped in dilutant. In this method, the initial color wash layer is later painted over with opaque paint mixed with white. A similar method can be used with traditional glazing technique or when a certainly watercolor-ish look is desired.

If you’re not used to painting without white, a good exercise is to try to complete a painting while using white only when absolutely necessary. That can generate an overall range of value and chroma that is markedly different than a painting in which white is used liberally. If you struggle with “chalky” mixtures, a minimal white approach can really help.

The whitest white I’ve been able to find is “radiant white” by Gamblin. It’s titanium white in poppy oil. Most of the time I prefer paints ground in linseed or walnut, but for this purpose it makes sense to use the whitest possible pigment and the most colorless binder available. I’m still painting out test strips on a neutral gray background, but I’d guess it’s a quarter Munsell value step than the next brightest titanium white I’ve played with. I’ll use it only when I need a very light highlight.

The darkest black I have is Williamsburg intense black. The pigment is listed as “carbon from gas flame.” The back label says: “warning: very slow drying.” It is just noticeably darker than bone (“ivory”) black. The slow drying can be compensated for somewhat with a drier such as lead napthenate. I will use it only for dark accents at the very last stage of painting, so drying time for this particular paint is not that important for me.

Update

2 May 2009:_ There’s a small highlight that I had previously painted in Old Holland titanium white. It’s light reflected from the shiny metal part of a clothes hangar. In real life this highlight is very noticeable, but on the painting, surrounded by relatively light tones, it did not stand out at all. I recently painted it in using pure Gamblin radiant white. It is noticeably brighter than before—giving an effect that is much more like what I was trying to depict.