Painting in Progress - Roman on the Beach 2/3

This is a time lapse of about 30 minutes' work. I was working on building up shadows and adding definition with purples, and adding other cool colors to the background. 

The ocean presented a special challenge. I never use white paint--for whites, I use the white of the paper (glazed over with very pale washes if needed, depending on what I'm painting). So I used frisket to mask parts of the background, in order to paint broad washes across the ocean without loosing the white frothiness of the waves. I removed the frisket after a few more washes, and after letting the painting dry. I don't use frisket very often--in fact, the last time I used it was in 2010 for my painting Solitude. The frisket I use is Winsor & Newton colorless art masking fluid, which is a latex product. Once dry, it rubs off with a fingernail or paintbrush handle and does not damage or stain the watercolor paper.