"He had a number of pictures on hand; most of them were too large and ambitious for his skill.He was the sort of painter who can paint leaves better than trees. He used to spend a long time on a single leaf, trying to catch its shape, and its sheen, and the glistening of dewdrops on its edges. Yet he wanted to paint a whole tree, with all of its leaves in the same style, and all of them different." "Leaf by Niggle" by J.R.R. Tolkien
