Pastels are a dry drawing medium that comes in finger-size sticks and has the appearance of chalk. Pastels tend to have a higher pigment concentration than any other artist medium because of the pigment to filler ratio. They come in a variety of shapes: round or square and thick or thin. Pastels come in three different types: hard pastels, soft pastels, and pastel pencils encased in wood. Each of these pastels has different qualities and attributes.
Pastels are made by mixing pure powdered pigments with non-greasy inert binders, such as gum arabic, gum tragacanth, or methylcellulose. The amount of binder determines hardness or softness. Hard pastels have more binder and less pigment, and soft pastels are the other way around. Soft pastels have intense colours, but they crumble easily. Hard pastels tend to hold their shape, but the colours are less intense.
Hard pastels usually come in a square or rectangular shape; they are good for clean lines and detail work. Soft pastels come in round shapes and are good for coverage and blending. Pastel pencil allows more control and is a cleaner alternative to soft pastels.