Polycolor blender pencils soften colored pencil edges and aid in blending and creating shadows. The blender pencil has a colorless 3.8mm core encased in California Cedar. California cedar is not only a renewable resource but is regarded as the best wood for pencils because it doesn't warp. Each core is perfectly centered in its casing for even sharpening, and glued throughout to prevent breakage. The end result is a water-resistant, non-toxic pencil that layers and blends beautifully without a waxy buildup. AP, Conforms to ASTM D-4236 Made in the Czech Republic