Dear Sharilyn, Recently, It was suggested to me that I might make soft pastel drawings on canvas. This got my attention because I have been wanting to use pastels while working outdoors this coming spring and summer. This also generated a lot of materials questions I was hoping you could help answer. Thank you, Simon
Pastel is one of the most versatile drawing tools available to the modern artist. Pastels contain minimal binder or filler and pastel paintings can be created on a myriad of textured surfaces. Since pastel application relies on the ‘tooth’ of a surface for painting or drawing, the only kind of support not suitable for pastel is a very smooth one, like Bristol or Masonite.
In contrast to pastel, paints have a binder in its vehicle which undergoes some chemical change to make the application permanent. In the case of watercolor, for example, the pigment is ground into a mixture that includes gum arabic, which dries and holds the pigment to the surface like glue. But pastels, usually just clay and/or chalk with pigment, don’t have anything to “glue” the pigment to a surface, they rely instead on the artist pressing the pigment into the nooks and crannies of a surface.
One certainly could paint on rough or wide-weave canvas (or linen, burlap, jute). However, a drawing applied to a surface like this would be very difficult to blend. Since most pastel painters value this quality in their materials, a rough or uneven surface is not desirable in most cases. A slightly rough paper provides an optimal surface for pastel application, due to the fine-toothed surface made possible by the pulped paper fiber.
The “snap” or give of a stretched canvas or linen, which might be desirable for painting made with brushes, would be really detrimental for pastels. Any movement of the surface would dislodge the applied painting. Pressing into a stretched canvas with fingers to blend pastels could unevenly stretch the underlying fabric and cause unsightly sags. A better surface for pastels would be a piece of smooth linen or canvas glued to a rigid lightweight support like MDF (Masonite) or ACM (aluminum composite). Many plein-air pastellists glue or temporarily affix toothed paper to a rigid surface. Another alternative would be to apply an acrylic pastel ground to any rigid surface. Golden makes a very nice acrylic-based pastel ground which is easy to apply. A pastel ground applied to a piece of MDF makes a lovely surface for plein-air work, and the artist can purchase boards already prepared this way from Ampersand among others.
Almost any ground is fine for pastel application, though an oil ground or thick acrylic ground would benefit from a light but thorough sanding with fine-grit paper.
3) Would a Turpenoid wash of color to start the picture change any of the above answers?
Turpenoid (or any OMS) is a petroleum-derived solvent and should not be used on an unprimed surface. It certainly can be used for pastel washes but it may take some time to dry completely, which is why denatured alcohol is more popularly used for this purpose, as it evaporates very quickly. Water can also be used as a solvent for similar techniques.
4) Finally, How would you suggest that I treat the surface in the end? Should I spray it and if so, with what?
To fix or not to fix a pastel surface is an aesthetic and not really a technical question. I personally prefer the look of unfixed pastel. If fixing, a spray fixative should be used in a well-ventilated area, preferably one recommended specifically for pastels. Sennelier and Lascaux both make excellent fixatives for this purpose.
Pastel dust is a health hazard if inhaled, so be sure to work in a well-ventilated environment and/or consider wearing a dust mask or even a respirator. Cumulative exposure to fine dust can have serious respiratory consequences. Any space dedicated to work with pastels should include an air filter, and work surfaces should be wet-cleaned at the end of a work session. Many toxic pigments are used in pastel painting and extra care should be taken in handling these so they are not aspirated.