Pastel crayons have been used as a drawing medium since the 15th century. The term "pastel" is derived from the Italian word "pasta" (dough), because in the past pigments were kneaded into a dough with the aid of a binding agent.
Polychromos Artists' Pastels were introduced in 1911. They are highly pigmented, hard pastels that are acid-free. 48 of 60 colors are rated with *** lightfastness providing intense, smooth color laydown. Unlike color pencils that adhere to just about all types of paper, they require a drawing background of a certain roughness. Pastel crayons are therefore mainly used for surface-covering on soft, fine-grained or velvety velour paper or on heavy paper with a coarse-grained surface. It is also possible to draw on stone or asphalt. This attribute extends the pastel crayons' application options. They can be wiped or treated with a paint brush.
Polychromos Pastel Crayons have a rectangular cross section. The shape allows several different line widths which enables the artist to draw fine details as well as working on large areas. This feature gives artists the benefit of ready "edges" with which to achieve sharp delineation when required, as well as flat sides to allow uniform tonal shading.