The basis of this painting was done back to front! I painted two layers of cobalt blue and then one of indigo before I started, adding more water as I moved down the page so that the bottom would be lighter. The cobalt blue is easy to keep smooth and even, the indigo much less so. I used a circle of masking tape to keep the moon white (and later softened its edges). I then removed color with a wet brush quickly followed by mopping with a paper towel. You can get almost all the way back to white paper with these two pigments (other colors are much more staining). The white on the fox's face and tail were not masked first, but just had their color lifted. I then added color to the fox, but the underlying blue helps keep him in the same moonlit spectrum of light - he doesn't show up quite as red in the actual painting. I added a little definition on the trees with indigo paint and a fine brush, but whereas I'd originally intended to make them clearly birches, I found that I preferred the softer focus of the subtractive process rather than defined markings. I also worked the middle section of the background so that it looks like a more distant hill.