These water-resistant crayons are soft and easy to work with. They feature exceptional covering power, excellent lightfastness, and are great for underpainting. Their hardness allows them to be sharpened more easily for detail and edge work. Crayons are soluble in mineral spirits for wash techniques. Each stick is 3/8" diameter _ 4" long(10 mm _ 102 mm). Usable on a variety of materials including but not limited to: paper, cardboard, glass, wood, leather, fabric, stone and more.Set of 15 Ü This set contains artist crayons in 15 colors, including White, Black, Yellow, Orange, Brown, Scarlet, Purple, Violet, Cobalt Blue, Emerald Green, Ochre, Vermilion, Ultramarine, Turquoise Blue, and Yellow Green.