I was very interested in the reproductions of your [ Calder's ] sculptures. I have looked at them many times [Calder sent him], and they are something completely unexpected. You are taking a path full of great possibilities. Bravo! Sculpture is of enormous interest to me right now. For the last two years [1944-46], during summer vacation, that's all I have been doing and it's very good for a painter to get away from the old story of canvas and frame every now and again.