There are soft pastels and oil pastels. Soft or chalk pastels are the original and most popular paste. They glide easily onto a paper's surface with the ability to produce many different types of strokes. This pastel has the widest range of colors available.
Oil pastels consist of pigment mixed with a non-drying oil and wax binder. Oil pastels can be used direct from the stick, built up in layers, blended with a cloth or even diluted with mineral spirits to create rich, transparent washes.