Hairspray vs artist's fixative
 

"[...] For an art spray fixative, you are paying for even dispersion of the spray and a good acrylate coating that will preserve your piece.

Some hairsprays will have the same ingredients as art fixatives, but be wary of the dispersal system (spray). [...]

Also, be forewarned that many hairsprays contain hair conditioners, which is usually another name for a natural or synthetic oil. These conditioners could leave grease spots on your art. The oils to avoid are dimethicone, silicone (anyone pretty much), anything 'oil' or 'lubricant', vitamin A or E (both are oil-based), anything ending with 'glycol'. Be wary of anything listed as a plant extract.

I would think the really inexpensive, no-frills sprays might work well [...}. Just look for an acrylate in the ingredients. Suspension in alcohol is probably better than in water.

The quality of the chemical isn't any higher in art spray. The concentration might be higher, but I think extra-stiff hairspray would have at least as much. The nozzle or sprayer may be better on the art spray and the formula may have been mixed to deliver an especially fine mist."

Original text from Dr. Anne Helmenstine (About.com Chemistry Guide), you can read the full article here: http://painting.about.com/od/pastelp...Qhairspray.htm

Last I looked, practically all hair-sprays as well as art fixatives available in aerosol "bombs" employ nitrocellulose lacquer as the "fixing" material. In the US, Alberto VO-5 is acceptable for the purpose as it has no objectionable adulterants, and is available un-perfumed. Hair-sprays would always be questionable, and require testing and full disclosure of the material contents to be acceptable.

Iso-acrylate may be a good (synthetic) resin for use as a pastel fix, but the volatile solvents necessary to disperse it as an aerosol would be pretty nasty.

Traditionally, natural resins (e.g., mastic, damar) were dissolved in 200 proof alcohol (to eliminate water) and applied with a mouth or bulb atomizer. Overall, this would be a less toxic and more eco-friendly approach at much lower cost.

Degas is reputed to have used casein preparations to fix his pastels, and currently, there is a casein fixative for pastel on the market. A thread on this topic was begun in the "Paints, Mediums, Brushes & Grounds" section, but prompted very little input.