When I should have been present and mindful in town today, I was thinking about the different ways in which I could use that drawing gum. So, as soon as I got home, I played with it a bit. I wanted to see if I could use it to create different shades in a painting.
So, having sketched out the leaves, I applied the gum to the two branches in the foreground. I then gave the whole thing a wash of blue watercolour and let it dry. Then I applied the gum to the leaves in the background, over the first wash. When that gum was dry, I gave the painting another wash of a darker blue.
When that was dry, I removed the gum with an eraser.
It’s a bit ragged, the result of not enough care shown in applying the gum but I succeeded in getting the effect I was looking for.
The advantage of this method over, say, painting around the leaves, is that you can get a uniform shade. Uniformity is difficult to achieve when painting around things.