The glass master goes to the laser beam recorder. The formatted CD-R, DLT tape, or DVD-R is thoroughly tested for data integrity & used as source material for the laser beam that records information onto the surface of the Glass. The recording machine creates exposed areas in the surface of the photoresistant coating. This results in a layer of digitally recorded information.
Rinsing the glass master with a developing solution removes all those areas of the film that have been exposed to the laser light. What’s left is a series of digitally encoded pits in the surface of the photoresistant. Then comes the turn of the sputtering machine used to deposit a thin film of nickel coating onto the surface of the master.