95% (or better) of the Studios that I can think of, spray their photos with sometype of finish to help prevent damage and minimize UV fading.
This isn't something new. All of the better labs do this (at extra cost per print) for their customers. Spraying protective coatings on prints has been around for years. However, even if you spray them, that doesn't protect them as well as framing them behind glass (conservation or museum quality) and sealing the back of the frame properly.
I have a spray booth in my sutdio and we still spray ALL of our prints with MacDonalds Proteca Coat Lustre, Matte Special or High Gloss Lacquer. There are water borne coatings, but I do not think they are as effective. The problem with spraying your prints, is the vapors that are associated with it. You have to have te correct equipment and a method eliminating fumes. DO NOT spray a print in your home, well unless your intent is to get high!
CJ