I sketch for two reasons: for the pure enjoyment of it and for planning my watercolor paintings. Like most artists, I used to sketch with a pencil, but I found myself using the eraser more than the lead. Thats why I made the switch to felt-tip pens. Through trial and error, Ive become very comfortable with the medium. As the pens begin to dry out, I use them for my light values. New pens work best for the dark values. When Im in the field, Ill do a 5 ? x 7-inch sketch of the scene. I spend no more than 10 minutes on a drawing. That way I can finish four to five sketches in an hour. Back in my studio, Ill complete the drawings by adding the light and dark values. I rely on my memory to put into the drawing what I think is most important.
I think of sketching and painting as two separate processes, so when Im working on a sketch I focus on making it as complete as possible. When the sketch is done, I turn my attention to painting. I dont draw on my watercolor paper. Using my black-and-white sketch as a reference, I begin painting directly on the surface.
Ross Merrill is chief of conservation at the National Gallery of Art in Washington, D.C.