Grumbacher Resist Sticks, 2 Pack are jumbo wax crayons that repel liquid when applied to paper or other watercolor substrates. When used on the first layer of a painting, it keeps the areas underneath it the color of the paper. Apply resist sticks on dry layers of watercolor to resist subsequent paint applications. Creates textural effects on cold pressed papers, smooth areas of watercolor resistance on hot pressed sheets. Extra large crayon to cover large surfaces of paint resistance. Super soft wax can be shaped with warm hands, sharpened with a craft knife or extra large sharpener. Crystal clear wax doesn't yellow; AP non-toxic, conforms to ASTM D-4236.