This is a lesson in overcoming assumptions.The mail I receive from readers trends strongly to the appreciative; it’s rare that anything remotely critical comes in, so I’m sure I’m completely spoiled.When I read this letter from a class near Philadelphia and saw that they were questioning a scene in the...

I like to think that the story I’m illustrating tells me what medium to use on it. And I have used quite a few materials over the years. But there does seem to be a preponderance of oil paints on the roster. Could this represent an actual preference on my...