Dad enjoyed experimenting with color, media and style. He would often choose a theme and play with it, varying one thing or another. It's possible that these faces were expressions of his mood, his dreams, faces he remembered...or simply imaginary faces that emerged from the techniques he was exploring. Wish I had asked. Usually, he would simply say, "I'm just experimenting. Having fun with it and seeing where it will go, what I can do with this technique." Exploring a particular technique was a way Dad used to keep himself interested and excited about his art. He painted or sketched just about every day.