These oils, along with other binders, allow the Polycolor pencil to create dense, even strokes without the use of heavy pressure. The 3.8mm lead diameter is an added artistic value to these pencils. The broad edge is excellent for shading, while a finely sharpened point creates exquisite detail. These leads are encased in California Cedar for easy sharpening. The end result is a water-resistant, non-toxic pencil that is suitable for all artists. Comes in Tin sets of 12, 24, 36, and 48 as well as a 36piece wooden box set.