There are two basic types of pastel papers: sanded and uncoated. Sanded papers provide varying degrees of tooth which help hold the pastel on the paper. My personal favorite, as that of so many other pastel artists, was for many years the papers made by Kitty Wallis. Sadly these are no longer available due to production problems. UArt paper, which comes in 7 different grades of grit, has worked as a reasonable substitute for me, although I miss the heavier stock of the Wallis papers. I find that it can take a lot of punishment and accepts various water based mediums for underpainting (I have been using 400 and 500 grit). It only comes in a light sandpaper color, but if you like working on colored paper, you can tint it with watercolors. If you are using water, be sure to tape the paper down on all four sides with drafting tape.
Sennelier La Carte Pastel Card is a beautiful coated paper available in wonderful colors. It can be an especially lovely choice if you want to leave the unpainted margins showing or have bits of paper show through the pastel. Be careful however not to get any moisture on it-even the tiniest drop of water will remove the coating, exposing the underlying white support which will not hold pastel.
There are a number of other sanded papers available in different finishes with different degrees of grit-I suggest experimenting to find out which suit you best. Sampler packs are available from Dakota Pastels. There are also a number of pastel boards which are especially useful for plein air painters.
Uncoated papers will not hold many layers of pastel, but may be a good choice if you work very lightly. Or try Terrages and Thin Line pastels created by Diane Townsend: they contain pumice to “open up” the surface of uncoated paper (see Introduction to Soft Pastels).
A unique coated paper is Pastelmat. On heavy stock card, it can withstand a lot of water, hold many layers of pastel, and comes in 8 lovely colors. It is velvety smooth to the touch and kind on your hands; the manufacturers claim it eliminates the need for fixative. I have seen beautiful pastels done on this paper and know pastelists who adore it, but I personally have had difficulty working with it. I find it grabs the pastel almost too strongly for my purposes, restricting the way in which I like to apply pastel to the support.
In addition to a paper’s tooth, its color can effect your painting in several ways. If you work lightly or leave the margins showing it becomes an important element in your picture. When using a paper with substantial tooth, tiny bits of the original paper often peek through. More subtly, both the value and hue of the paper will effect your choices of pastels and their appearance. You can see this for yourself by trying the same color pastel on different tints-try white, a neutral gray, and a dark color paper for comparison. The three small papers with the blue and pink swatches on the lower right in the above photo gives some idea of how different pastels can look depending on the color of the support. The same medium blue and the same pink pastel are on all three papers. Many artists find that in general midrange neutral tints give them the truest colors. But neutral midrange tints are not the only choice for a successful painting and colored papers can also be used more boldly. They can be used to create mood and enhance the palette of your picture, either by emphasizing it or choosing a complementary color to create vividness and complexity. For example, you might choose a blue paper for a predominantly blue seascape or experiment with how an orange undertone might effect the look of your painting.
If you are working with mixed media and want to add pastel to a surface not intended for it, (for example on top of metal leaf), y0u need to apply something to the support so that it will hold pastel. Golden Acrylic Ground for Pastel is made expressly for this purpose and has worked well for me; it can also be fun to experiment with other acrylic grit mediums to achieve different surface textures. (For examples of pastel applied on top of gold leaf, see Alchemy Series).