Gwenneth,
I agree....pastels are a "good thing"!
I'll have to check out Mr Mayer's book...I regret to say that I'm not up on all of the latest technology. Although I am not usually involved in the framing aspect, I always educate the client as to the importance of NEVER letting glass touch the surface, and that if a mat-less look is desired, make sure the framer elevates the glass by building up a "buffer-zone" behind the frame, between it and the artwork. It very well could be a case of too much fixative, thinking that more was needed to keep the darned pastels in place!
But, now I know...thank you for your response...tsch