An exercise in flat wash technique
This is the first exercise that all my students must complete. You absolutely must be able to do this. If you try to do this exercise, the goal is a perfect result, otherwise you will have to do the exercise again. If the result is bad, you have to keep practicing until it becomes good. It is absolutely basic, you have to learn to crawl before you can run.
You will need: Paper, at least 8X8 inches (20X20 cm) in size. A larger brush. Something to mix the colors in. Colors, a blue and a brown (and possibly a cold red). The blue color should be a color with small light pigment grains, e.g. phthalo, antwerp or indatren. It is difficult to do a flat wash with ultramarine or cobalt because the pigments granulate.
The brown should be orange-reddish brown. It does not work with yellow-brown colors.
Bring out your paper that is at least 8 inches (20 cm) in size. Draw a cube with one corner facing the viewer. The cube should be approx. 5 to 6 inches (12 to 15 cm) wide. If the cube gets a little crooked is perfectly fine, this is not a drawing exercise, a crooked cube works as well as a perfect one.
Mix your blue color, it should only be diluted with water, you should not have any brown in it. If you mix in more water, the color becomes lighter, with more paint it becomes darker. Feel free to test the value of the color on the paper before you decide.
Make sure you have enough paint to paint the whole cube, it takes more than you think. You do not have the opportunity to mix more paint if it runs out before the cube is finished. Rule of thumb: It takes twice as much paint as you think, If you have leftover paint when the cube is painted, it does not matter, it will be used later in the exercise.
Tilt the paper, you can just hold it in your hand slightly tilted, or place an object under the paper for the tilt. the simplest is probably to tilt the paper against something suitable, it is also better for it to preferably dry tilted, with something under the paper you do not have to hold it while it dries.
Start painting in the top of the cube, you should paint with a lot of paint in the brush, then the paint will run down and form a long bead. You move this long bead down over the paper with horizontal brush strokes. Paint fluently, it should be a lot of paint, otherwise you risk getting visible brushstrokes in the wash. Continue until the whole cube is painted. When you are done, the cube should be blue with no visible brush strokes. You will have a lot of excess paint on the bottom edge.
Excess paint at the bottom of the painting is removed as follows: Drain as much paint as you can from the brush on the edge of the mixing cup Then place the brush tip against the bottom of the cube, where the paint has collected. If you tilt the brush so that the shaft is lower than the tip, it works better, at least with a simpler brush. Soak up as much paint as possible, repeat the same procedure until all excess paint is gone.
Now you should paint a shadow on the cube, wait until the blue color is dry, then mix the brown color in the blue color that was left over from the first wash. With a little luck, the mixture turns gray. I used phthalo blue, it turns green with any brown, in which case you have to remove the green tone. This is done with the help of the complementary color to green, which is red, a cold red. I used Quinacridone Rose, but it works well with any cold red. Summary: mix blue and brown, if the resulting gray color becomes greenish, mix in a little red so that the mixture becomes neutral gray.
When the gray color looks good, paint the whole cube except the top part which should be blue. Do the same as when you painted the blue color, start at the top, paint the entire surface, soak up excess paint.
Wait until the shadow has dried and then paint one of the fronts (right or left does not matter) one more time with the same color.
If you now have a nice even blue cube with good shadows you have passed the test, if you cube is uneven or the shadows are too dark or too light or uneven you have not succeeded, then just repeat this again and again until you pass of the test. You must be able to perform a flat wash, it is a crucial when it comes to watercolor painting.