Direct placement of glass on Pastels?
 

Is there ever a time when placing glass directly on pastel paintings is acceptable?

Nope, never.

PS Why do you ask?

Framer asked
 

A framer friend of mine asked. Someone brought in a pastel on a velvet paper and she was concerned how to mount and frame this kind of paper.

I told her never to place glass on pastels, but she was under the impression it would be o.k. because of the type of paper used.

Weird question I know, but you confirmed the information I already knew.

Thanks!