Top-quality materials, combined with Faber-Castell's long experience, ensure that Polychromos artists' colour pencils have extremely break-resistant leads, maximum light-fastness, the most vivid colours and optimal paintability, along with many other advantages valued by professional artists. Polychromos pencils feature an oil based binder. This makes the material water-resistant and less likely to produce wax bloom. If you are accustomed to using wax based colored pencils, then you will definitely notice a different feel to these pencils. They spread over the surface very easily and layer nicely.