What to tell your framer:
You want acid-free, archival framing materials. The backing board and mats, if any, should be museum quality. 100% rag board and acid-free foamcore is best. Cheap mat board or brown cardboard backings will stain and yellow your painting within a few years.
Do not spray any sort of fixative or coating on your painting in the framing process or allow your framer to do so. Careful handling is a must. Do not touch the painted surface. Putting fingers or other items on top of the painting or allowing it to be rubbed or flexed will damage the surface. Keep it flat, supported from underneath and facing upwards to protect the pastel surface.
Choose a framer who is experienced in working with fine art pastels. A framer who works mostly with posters and printed reproductions or oil paintings may not realize that pastels take special handling. Do not risk the welfare of your painting in the hands of an inexperienced framer.
Paper Mounted or Solid Surface - If your painting is already mounted on a surface, it can easily be framed with no mat but use a spacer strip between the glass and the painting, so the pastel does not touch the glass surface. Your framer may choose to seal the edges.
Paper (not mounted) - If your painting is a paper surface, one good approach for framing your pastel is to use a reversed double mat, with the larger window underneath. This creates a gap behind the mat where any fallen pastel particles will be invisible. Otherwise, it could be mounted to an acid-free surface and placed in a frame as described above.
Do not use Plexiglas™ or non-glare glass to frame your painting. Plexiglas™ holds a static charge that may pull pastel particles from the paper and in time create a “ghost” image on the underside of the glass. This will probably not seriously harm your painting, but it will obscure your view of it! Non-glare glass makes your painting appear blurry and dull in color, and it is best avoided. Museum glass or anti-reflective glass should be used. I prefer museum glass, but it is more costly. If you clean the glass on your painting, be sure to use a clean, soft, lint-free cloth to clean the glass, like a microfiber cloth. Spray a small amount of ammonia-free clean ONTO the cloth (NOT on the painting to avoid getting liquid behind the glass). Clean the glass in round, circular motions.
Hanging your pastel:
Just like with any painting (oil, acrylic, watercolor, or pastel), choose a dry place indoors out of direct sunlight. Sunlight, even filtered through a window, is the enemy of all fine artwork. It degrades paper and canvas and may fade pigments. However, museum glass helps protect it from sunlight. An interior wall without nearby windows is ideal. Bedrooms, sitting rooms and hallways are often the best places for fine artworks. Bathrooms and kitchens may have very damp air, so please avoid hanging your fine artworks near showers, tubs and stoves.