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From: Patent Tactics, George Brock-Nannestad


----- are they not etched into the glass afterwards? What is the photoresist 
resistant against?

George


> Regarding CDs, the pits are in a thin photoresist layer that is spun onto
> the glass substrate.
> 
> Jerry
> Media Sciences, Inc.
> 
> > -----Original Message-----
> > From: Association for Recorded Sound Discussion List
> > [mailto:[log in to unmask]] On Behalf Of George Brock-Nannestad
> > Sent: Saturday, January 22, 2011 6:09 PM
> > To: [log in to unmask]
> > Subject: Re: [ARSCLIST] How many 78s to the Matrix
> > 
> > From: Patent Tactics, George Brock-Nannestad
> > 
> > 
> > Hello,
> > 
> > Stewart Goodeman wrote [quote]:
> > 
> >  I know in 1943, when they recorded the Rodgers and Hart
> > > revival of "A Connecticut Yankee" they actually used glass.
> > >
> > 
> > ----- just to avert any confusion: glass means that the disc that
> > supported
> > the layer that the cut was made in was made of glass. The layer could
> have
> > been lacquer, or it could have been wax, both were used. It has been
> > thought
> > that glass was a cheap substitute for aluminum that was the most used
> > material for lacquer mastering discs, due to other uses for aluminum
> > during
> > the war. But in fact, the quality of the cut in glass-based discs was
> > better
> > than for aluminum, because the surface of glass was much smoother.
> > 
> > This is very different from the use of glass in the manufacture of CDs;
> > here
> > the pits are really represented in the glass as a stage of manufacture.
> > 
> > Kind regards,
> > 
> > 
> > George