This is the underpainting for one of my recent works called Tower Arch. Sometimes I enjoy starting a painting on a white canvas, but other times I find it helpful to "tone" the canvas a neutral color. I typically use raw umber thinned with mineral spirits for this purpose. Whether starting from a toned or white canvas, I often use a simple monochromatic underpainting to work through form and composition choices and to define values for use in subsequent layers. Lightness and darkness become more difficult to articulate once local color is applied, so an underpainting can serve as a guide on which to build more colorful layers.
