Sennelier - Grand Oil Pastel - 38 ml - Blue Violet - First created in collaboration with Picasso in the 1940's, these ultra creamy pastels are rich in pigment, cover well, and have remarkable opacity and lightfastness. They can be thinned with turpentine and worked with a brush, are acid-free and can be applied to any surface. Sennelier Grand Oil Pastels are the equivalent of 8 regular size oil pastel sticks.