Polycolor is professional grade line of pencils that use Koh-I-Noor's unique blend of oils and premium pigments in every color core. 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 allows for shading with a broad edge, or fine sharpening for detail work. These leads are encased in California Cedar, a renewable resource that is the gold standard for pencil casings. The end result is a water-resistant, non-toxic pencil that layers and blends beautifully without a waxy buildup.