I suggest you follow Sandy's suggestion as I've only done this once.
Woody
Sandy Bacon wrote:
> Be careful of the type of glass or plexi you use. Glass itself can have
> acidic properties depending on how it is treated, I believe. You also
> may want to invest in glass (UV) that will protect your work from sun
> and flourescent light. It has always been my policy, too, not to have
> the glass touch the artwork because you don't want to risk the chance of
> any moisture building up between the glass and the piece. I would
> suggest spacers between the glass and the frame to secure the glass in
> place and allow the piece to float. Always use linen or acid free tape
> to adhere the artwork to mat or ph foam core. Just a couple of tips
> from an old framer,