Yes, an underpainting serves as a fundamental purpose, to set the values, and overall color, tone and temperature of a painting. Used beyond the rudiment purpose, underpainting can enhance the energy and interest in a painting, creating a layered effect and the illusion of depth and volume.
Over the past year, I have been exploring the possibilities of underpainting in watercolor and applying it to pastel landscapes...some small, others much larger as this one is. The tone, value, and color are established in watercolor, allowing for the watercolor to do what it does best...create a wonderful mingle of little explosive color blossoms. Then, pastel is applied, allowing for some of the subtle watercolor creation to show through, enhancing the illusion of air and space.
I will have 10 or so of these pastel landscapes on exhibit at Kybecca September 1st through October 31st.