21 July 2009

Color Charts

My lack of color knowledge slowed me down in the introductory painting classes I just finished. There was some discussion in class about mixing, but the palettes we used were limited to just a few colors. I realized the only way around the problem was to pick some colors for a starter palette and do some color charting. Since I just finished reading Alla Prima, which has a good chapter on color, that seemed like a reasonable place to start.

Richard Schmid claims he can mix most other commercially-available tube colors from a palette of 11 colors which includes 4 yellows (cad lemon, cad yellow pale , yellow ochre pale, cad yellow deep), 4 reds (cad red, alizarin permanent, terra rosa, transparent oxide red), a green (viridian), and 2 blues (cobalt light, ultramarine). I like the idea of learning to mix with a set number of choices.
Schmid describes how to prepare the charts in detail in his book. Briefly, I gessoed a dozen 8" x 15" pieces of heavy illustration board, taped off 5 rows x 11 columns of 1" squares with 1/4" masking tape, then mixed and applied the colors. Each board represents a predominant hue mixed with a smaller amount of each of the other hues. Each of these mixtures is then combined with white to produce 5 graduated values. It took about 3 hours per chart.

I took my time and tried to spot the similarities and differences between colors within each family; made mental notes on how to mix common hues; noted the shift in hue of a color combination as one color predominated, then the other. It was really exciting to pull the tape off the finished charts. They're gorgeous in real life. I felt like I was printing money, generating this wealth of beautiful colors. I didn't post the individual charts here because the reproductions are so inferior to the real thing, but if you click on the group image above you get an idea of the color diversity. The upper left chart shows the gradations of the original tube colors.

I mounted the charts on the wall near my easel for easy reference. A good exercise is to pick a color in the surroundings, name the combination of 2 tube colors to arrive at that color, then check that guess against the charts. Only 2 tube colors per mixture to avoid the mud. Also, if you haven't yet, take a look at David Rourke's discussion on color mixing in his blog, All The Strange Hours. Finally, Bruce MacEvoy offers a complete discussion of color at his blog Handprint, with some useful value and color mixing charts (TY to David for mentioning Handprint).

14 July 2009

Color Intensity Study

Color intensity is important for conveying changes in the quality and location of light sources in a composition and in atmospheric perspective. Here's a good exercise for learning about color intensity from the introductory painting class I just finished with Lucas Graciano. We were given a landscape photo and told to paint it as a high, medium, and low intensity image without changing value. There are 2 ways to do this. First, mix the appropriate color, then add either the complementary color of the same value or a neutral gray of the same value. I opted for the neutral gray approach, using a set of 4 grays of increasing value that I pre-mixed from ivory black, titanium white and small amounts of raw umber (to balance the coolness of the ivory black).

The top left image above is the original photo. Next are the high (top-r), mid (bottom-l), and low (bottom-r) intensity paintings. I wasn't trying to render, just get a decent read of the big shapes. In hindsight, the low intensity image should probably be less colorful. I followed Richard Schmids' method, described in Alla Prima. He mixes the paint for each brushstroke based on the color, value, and intensity of the adjacent shapes. Once applied, if the stroke/shape is not correct he removes it immediately. His advice: Never leave a mistake on the canvas.

You can learn a lot from this type of study about intensity, and also about color mixing in general. Time well spent if you're just starting out. So, how did I do on maintaining the values? See the grayscale conversions of my paintings below. Not too bad, could be better. I'll work on it.

In his blog, All The Strange Hours, David Rourke posted a useful article on color and color mixing, with a great section on intensity, which he calls chroma (about half-way through the post). His blog is worth visiting, lots of good posts.