Q. I haven’t used a fixative for my pastel paintings for more than 30 years because of the fixative’s tendency to change the color of the pastel pigment. I’m considering integrating more wax-based pastels just to try the metallic pigments, though, and would like to start using fixative again. What fixative(s) would you suggest to use with multiple brands and types of pastels?
A. Fixatives can alter the refractive index of many pastel colors, especially those light tints that contain chalk: The chalk goes transparent if the fixative is too heavily applied, and the colors can darken and change. But this effect can be mitigated by more carefully considering what a fixative is supposed to do.
A fixative must not be applied as a coating; it should be thought of as a “barely there” mist. It’s not intended to fix the particles of color to each other and to the support, but rather to gently prevent the dislodging of the topmost layer of pastel from the rest of the painting. Properly fixed pastels will retain their vibrancy of color, but they will remain very fragile. This is the reason many museums refuse to lend their more valuable pastel works to other museum exhibitions. I remember seeing an Edouard Manet pastel at the old Jeu de Paume museum in Paris that had a very fine line of color on the lower edge of the mat where the pastel particles had been dislodged by the vibration of footsteps from hordes of passing tourists.
To attempt to seal the pigment, it’s a good idea to practice your spraying technique. If you’re working on a pastel and intend to add another layer, use a light spray on the painting-in-progress while it’s still on the easel. When you’re ready to apply the final layer of fixative, lay the picture flat on a tabletop and, holding the sprayer at about a 30-degree angle at eight inches away from the picture, rapidly spray across the entire picture plane so the fixative falls in a light mist over the whole painting.
You can use any brand of fixative that’s labeled “archival” (though I don’t like to see that word used in this context). You’ll probably find that the best fixatives contain an acrylic or polyvinyl acetate resin, combined with ultraviolet light absorbers and inhibitors, a solvent or two, and, of course, a propellant.
Before you do this, let me offer a word of warning: Spray fixatives contain hazardous ingredients and can be dangerous. In fact, spraying anything can be hazardous. Read the label and follow all precautions, which probably include the phrase “use with adequate ventilation.” I’d rather wear a respirator or use direct local exhaust. At the very least, work near a powerful window fan.