Verithin is a brand of pencils made by PrismaColor. Available in 40 colors, Verithin Pencils are a wax-based colored pencil that are marketed as having a firmer / harder lead than standard Prismacolor pencils, and can be sharpened to a fine point with less crumbling. They are useful for making lines and fine details. They are hexagonal (six-sided). Despite being available in 40 colors, they don't seem to ever have been available in sets larger than 36; the four additional colors (Blue Violet; Non-Photo Blue; Magenta; and Red / Blue) must be purchased separately.