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Plexi question.,.....


CGF II, Certified Grumble Framer Level 2
Sep 7, 2002
I sold a customer plexi for a map 42x48. He calls me today and says his friend told him not to use plexi because it outgasses and causes damage to the art.

Now, I have been framing many years and have never heard of this problem. However, I told him I would research it just to make sure.

Whadda think? Any takers here? Of course, I am sure that his friend definitely knows what he is talking about (grrrrrrr).
Most museums use it (acrylic) rather than glass. I think the main reason they use it is that it doesn't break as easily as glass. Point being, they sure wouldn't use it if there was any possibility that it would affect the art. His friend may be thinking of the old plastic stuff(who knows what that was?) that turned yellow in time.

I'm sure if you told your customer this, he would be satisified.
plexiglass [poly(methyl methacrylate)]

is an electrical insulator... but off-gasses part of it's bindry compound thus becoming less than clear and eventually due to internal stresses accumilating micro fractures which result in glassing failure.

Acrylic on the other hand, does not have four fingers and a thumb as believed; But does exibit the following qualities...or characteristics.

Acrylic Plastic
Half the weight of glass
Impact resistant
Unaffected by sun or salt spray
Temperature range of -30 to 160° F for continuous service

Notice that "off-gassing" is not one of its traits.

If your customer would rather have his friend do his framing for him.... let him.... :D
Plexiglas is a brand name of acrylic.

Kleenex is a brand name of facial tissue.

Jello is a brand name of gelatin.

I think your customer's friend is outgassing. My favorite customers - the easiest ones to work with - are the friendless, motherless ones.
Originally posted by Ron Eggers:

I think your customer's friend is outgassing. My favorite customers - the easiest ones to work with - are the friendless, motherless ones.
Ron, can I quote you? I guess I already did...that is the funniest thing I've read on the Grumble in a long time!
I'm in full agreement with Ron.

Plexiglas is a brand name of the PMMA acrylic developed by Rohm & Hauss in the early '30's. It was used extensively during WWII for the windscreens of fighter aircraft and is a water white material that is impact resistent in thicker sheets. Many of the old fighter aircraft in museums today still have the original Plexiglas in their canopies and it is as clear as when it was manufactured. (Less the wear and tear of age on it.)

Like Ron, I would take anything a "friend" tells someone with a grain of salt until I check out the authenticity of their claims.

For further reading go to

Rideout's webpage


the Plexiglas webpage

Acrylic sheet is used with the most sensitive and
valued items in museum collections, in frames and
in cases. Its chemistry has not been shown to affect these materials in its many decades of use.
If it is heated, to its melting point (as happens
during cutting) methacrylate momomer is emitted;
as one's nose will attest, but in normal conditions, it is safe.