I had a pastel come through the shop recently and I realized I haven't done a post on pastels. Ever.
There's nothing terrifying about framing pastels, but there are some tricks.
Pastels as a medium are available in either oil or chalk. In either case they should be framed under glass, and the art should not touch the glass under any circumstances. There's a handful of ways to do that. This is one of my favorites.
Below is a young person's very awesome chalk pastel interpretation of Van Gogh's Starry Night.
Chalk pastels, no matter if they're spray fixed or not, are powdery. The chalk dust WILL sprinkle down over time--just a little, but enough to soil the bevel of a mat. That's just the nature of the medium. And gravity. So to combat this problem, we create a space for the dust to go.
I cut a piece of acid free foam board to be a surface for the mat to go on. This creates a 3/16" channel between the art and mat.
Below the foam board is cut with an opening about 1/2" wider than the mat will be.
The mat goes on top of the foam. Since the foam was cut wider, it is not at all visible. The gray mat appears to be hovering over the art.