RE: [AV Media Matters] medialine CD-R permanence article

[Charles Repka <Charles.P.Repka@abc.com>]

Regarding Kris Solem's comment's on the Medialine CD-R article (
which I have not read yet).  I agree with him that any change in
BLER is likely not due to the change in rotational speed.  As he
points out, the linear speed remains constant and therefore there
are no aperture effects.  I suspect the culprit may be due to the
pressing process.  As a general rule in disc manufacturing, ( and
this is true for vinyl LP's, Laserdiscs, CD's, DVD's etc) the inner
diameter of the disc tends to have fewer mechanical problems caused
by plastic flow during the pressing process.  The farther you get
away from the center, the more problems you see.  The higher BLER at
outer diameters may be due to problems with the servo tracking of
the wobble groove on the player used.  The wobble groove itself may
also be slightly deformed at outer diameters.  The deformation, in
turn, can be caused by pressing problems when the blank was pressed
or by problems in the mold used.  There are a lot of inter acting
factors here and it is not wise to just blame the dye. A lot more
data needs to be taken.

Charles Repka