Hi Matt.

11-Dec-03 02:06:51, Matt Mc_Carthy wrote to CHARLES ANGELICH


 MM> Saturday I was cutting up some 'replacement CD washers' and was
 MM> thinking of my previous discussion on CDs in the sunlight, and how
 MM> brittle and flaky the ones I was presently trying to cut were.  It
 MM> was almost like trying to cut 'Plexiglas' with a hatchet, they
 MM> just crazed and cracked randomly every which way.

what do youmuse them for?
have you tried cutting them with a smooth diamond cutting wheel in an
anglke grinder, they cut most plastics pretty well.

 MM> I had a few
 MM> DVDs in the pile and tried cutting those instead.  To my suprise,
 MM> they separated easily into two extremely flexible layers of about
 MM> equal thickness. My _guess_ is that the data layer was in the
 MM> center, but there was nothing as obvious as the CD data layer.
 MM> ???

DVDs have two data layers and select whuch one to read by focusing the
laser on it. the de-selected layer is then out of focus so it doesn't get
seen. I guess there's one layer right under the label like CDs have,
and another about half way through the plastic.
---