It’s not easy painting green

To paraphrase Kermit the Frog, “It’s not easy painting green.”  Not because it’s a boring color but because there are so many permutations of it, and most green paint pigments do not simulate the most common variations found in nature.  But greens are also difficult to avoid because they are so prevalent in most landscapes.

Unfortunately, the most common (single) green pigments, such as terre verte, viridian, and the phthalocyanine greens may mislead us into thinking that, because they are “green,” they are automatically right for the job.  That is rarely the case.  So what’s an artist to do?

Phthalo green (PG7, the somewhat bluer version, or PG36, the slightly yellower version) is an extremely strong stain, with a cool bias, and a hue not normally found in natural foliage, though it could prove useful in depicting the strong, deep greens of stones like malachite or emeralds.  Because the staining power is so strong, very little is needed to blend with most other colors. But because of that, it can be difficult to control, especially for inexperienced artists.

Viridian (PG18) is also a cool green, with a similar hue, but it has a weaker strength so is easier to control.  It can prove useful for some blue-green foliage or for sky-lit reflections off warmer foliage greens.  (Be careful–paints labeled “viridian” or “viridian hue” are sometimes actually made with the less expensive PG7, phthalo green. Check the pigment number on the packaging.)

Terre verte (PG23, also called green earth) is one of the weakest green pigments, with a somewhat warmer temperature bias than viridian.  Because it is an earth pigment rather than a stain, it is one of the few green pigments that can easily be lifted off a painted surface.  But it may be difficult to obtain a dark value with this pigment.

Additional single green pigments include the cool cobalt green (PG19) and the warmer but dull chromium oxide green (PG17).  Fortunately, any of these pigments may be mixed with other hues to vary the color.  And they frequently are, to create more usable “convenience” green paints, such as Sap green, Emerald green, and Hookers green.  But why limit ourselves to those?

It will help if we recognize that “green” is a secondary hue, derived from a combination of some variation of the primary hues yellow and blue.  So if we begin with those primary pigments instead of with a single green pigment, we may have better success finding a version of green that we really want.  Or we can blend one of the green pigments we already have with one of those primary pigments to change its temperature bias, making the green appear either warmer (yellower) or cooler (bluer) than the original green pigment, and moderating the chroma as well.  (It’s usually easier to dull a color down than to brighten it up.)

I will not attempt to reproduce a color wheel here because the colors may not show accurately on every screen anyway.  I recommend obtaining a color wheel if you don’t already have one to refer to (preferably a Munsell-based color wheel as the color positioning is more accurate for color mixing than on the more familiar triadic color wheel).  Although printed wheels might show hues as discrete blocks of balanced color, the color wheel is actually a continuum of hues, flowing from one into another, each balanced hue also having both warmer and cooler variations.

Hues close to each other are called “analogous.”  Hues across from each other on the wheel are called “complementary.”  The more analogous two hues are, the less radically they will change each other when they are mixed.  The more complementary (distant on the wheel) they are, the more the color will change and the grayer or more muted they will become.

The amount you use of each hue will depend on the degree to which you want to adjust the colors.  If you want just a little change in temperature bias, look for an analogous hue.  If you don’t want to change the temperature at all but do want to mute it, choose a little of the complementary hue.  If you want to change both the temperature bias and lower the chroma (gray it down), select a hue that’s analogous to the complement.

The method is to find the wheel location of the hue with which you’re beginning the mixture, decide whether you want to warm it or cool it, and how much you may want to gray it down.  Then locate a hue you think might be appropriate to mix it with to create the desired color.  Test it and see.  If it’s too warm or cool, or too gray or not grayed enough, try again.  It may take several tries before you find the variation you want, but don’t get discouraged.  With practice, you’ll soon develop a knack for being able to guess more accurately the first time.

However, you will need to be aware that blending is not a question of the amounts of the colors but balancing the strengths of the colors being blended.  For instance, you would need a LOT of yellow (which tends to be weak) to change a LITTLE phthalo green (which is extremely strong).  Try to start with the weaker color and add the stronger color to it, a little at a time, to find the desired balance.  (If you start with the stronger color and add the weaker one to find the desired variation, you could waste a lot of paint, winding up with a lake instead of a puddle before you achieve the color you want!)

Try blending each of your green paints with small amounts of your other colors to see what results you get.  Then try blending all your yellows and blues (yes, all the variations of them) in various proportions to see even more results.

Chart-of-yellow-blue-blends

Here’s part of a chart I made to explore some of the greens available to me in my existing watercolor palette, using just various blues and yellows.  But the technique isn’t limited to watercolors, nor to those hues alone.

You, too, can create reference charts using the colors in your own palette.  Be sure to make note of the name of each pigment so you can recreate the blend as needed in the future. Don’t forget to experiment with combinations of your existing green pigments with browns, oranges, reds, and purples as well as with yellows and blues.  You may be surprised at the usable outcome.

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