CD-RW

[Lennart Sorensen]

On Tue, Mar 04, 2008 at 07:09:48AM -0500, Mr Chris Aitken wrote:
> Is it really pressed (loosely analogous to vinyl record pressing) as 
> opposed to burned - or are you just nostalgically referring to 
> store-bought CDs (from a CD music store) as "pressed". Really, what I 
> want to know is can you "press" CDs at home?

Commercial CDs are in fact pressed just like vinyls.  Much faster and
cheaper.  This is why they work with old single laser DVD players.
There are physical pits that they can focus on, while a CD-R has a dye
layer to block reflection of a certain wavelength of light (which is not
the wavelength of a single laser DVD player).  Anything using a CD
player laser is fine with CD-R though since they still get the right
reflection.  CD-RW has less reflection and needs a more sensitive pickup
to detect the reflections which makes many players unable to read them.

So nothing nostalgic about refering to them as pressed.  They
literally are.  You don't make much money on CDs if you have to spend 5
minutes each making them.  2 seconds is much more profitable. :)

Sometimes you get very bad quality CDs that have errors due to someone
trying to use the same mold for too long or using a low quality mold in
the first place.

--
Len Sorensen
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