Soft pastels are a wonderful drawing medium. Pure pigment bound in a stick. They are a very flexible medium as you use them as a crayon or pencil getting the thinnest and most energetic line, or you can use the sides of them and get great swathes of colour. You can mix the colours by layering one colour on top of another. Or you can merge and fuse using a smudge tool or your own fingers.
Pastels are done on special tinted pastel paper which is usually a mid-tone neutral colour that suits the tone of the subject. For portraits I usually use a paper with a green/grey tint as this brings out the warm skin tones well.
The largest paper that I use is 50cm x 65cm. This comfortably fits a life-size head and shoulders, or a small ¾ length. But it is a limiting factor for the bigger ¾ length portraits.
Although you can fix pastels, they are still a volatile medium meaning that they can still be smudged or damaged even after applying fixative. Therefore, a pastel portrait must be glazed with a double mount in order for the glass to sit sufficiently far from the image. This adds about 8 inches to the height and width of the portrait (3 inches of mount and 1 inch of moulding all the way around).
An unframed head and shoulders in pastel will cost £1850. A 3/4 length ‘attitude’ pose starts from the same price up to £2500 depending on the amount of detail involved.
Since they are a drawing medium, the end result of a portrait done in pastels is informal and quite sketchy, giving a quality of freshness and immediacy. They are much cheaper than an oil portrait. This makes them a popular choice for a head and shoulders. Or a 3/4 or full body sketch.