One source of the product touted at the Texas Assn. of Museums is:
GS Images
PO Box 1288
Hagerstown, MD. 21740
(301) 791-6920
Fx 733-5379
They do a good deal of this for the National Park Service. Their product
is screenprinted original art/design, embedded in fiberglass. It survives
quite well in the harsher climates of the Appalachian mountain chain.