i specification c o v e r s the r e q u i r e m e n t s for t w o c l a s s e s of
t r a n s p a r e n t m o n o l i t h i c , m o d i f i e d , m e t h y l m e t h a c r y l a t e f l a t s t r e t c h e d s h e e t s
t h a t may be formed i n t o parts h a v i n g s u p e r i o r c r a c k p r o p a g a t i o n and craze
resistance as a r e s u l t of p r o p e r h o t s t r e t c h i n g ( s e e 6 . 4 . 2 ) .