Wallis Paper when I first started painting. I met Kitty Wallis back then and she generously gave me some samples. Wallis paper is unique, it is "sandpaper" (a very high grade) designed to "grab" your dry or wet media. I have used it for both pastels and oils. Every now and then I like to do a sketch on Wallis...because of the unusual sensation of that "grab". It seems the contrast can be much greater on Wallis paper than on any other artist paper.
I sketched this image and then dampened an old brush with mineral spirits, dragging it through the drawing to create some blur. If you use a brush on Wallis paper you just have to make sure it is an old brush you don't care about. (The sandpaper damages your brush).
Sketch (an idea for a painting): Celeste Bergin, Waiting in the rain, Charcoal on Wallis Belgium Mist, cropped to 6 x 12