O-Matter is a catch-all for Oakley's special recipe plastics, much like:
- X-Metal is their proprietary titanium alloy
- O-Luminum is their proprietary aluminum alloy
- O-Metal is their light, flexible metal used in some RX frames
- C5 is their standard wire frame material
Not sure if O-Matter is any one specific formula, either. For example, most modern O-Matter frames are much less brittle than older gen Eye Jackets. Also, crystal/translucent frames have a different "feel" compared to opaque frames, which seems to suggest the plastic is different.
Weren't the original Mumbo frames made of "Virgin Serilium"? What the heck is that?!