There tends to be a lot of confusion between the two types of technologies used in the CD production industry. There is CD replication, and then there is CD duplication - this article will explain the difference between the two processes.

People tend to be more familiar with the phrase CD duplication because it's the process that you are able to perform on your own home computer.

In short, you use a program on your computer to automatically copy your selected content onto a pre-manufactured CDR (the 'R' stands for 'recordable'). This is very simple and convenient to do when you only require a small number of discs.

► Does not require specialized equipment or training - can be done on
    a personal computer.
► Cost-effective for small quantities of discs.
► Can produce small quantities of discs relatively quickly.

Phase 1: Glass Master and Stamper

The first step in the replication process is creation of the 'stamper'. While this process is highly specialized and technical, the following explanation is intended to be very basic:

◦ A piece of highly polished glass is laser-etched with the digital data from the client's content master. Note: The data from the client's content master is not altered or changed in any way, it's strictly a transfer of data.

◦ The laser-etching creates pits and lands in the glass in a tightly grouped spiral pattern emanating from the center and progressing outwards.

◦ The Glass Master is then metalized, but it is far too fragile to be used to replicate discs so the data must now be transferred to another material that is resilient enough to handle the replication process.

◦ The metalized Glass Master is electroformed with nickel to produce a "father" master which is a 'negative' image as it has bumps instead of pits.

◦ The father master is then electroformed with nickel to produce "mother" masters which are used as 'stampers' in the injection molding process.

Phase 2: Injection Molding

Now that the 'stamper' has been made the replication of the CDs or DVDs can begin. Again, the process is highly specialized and technical, so the following explanation is intended to be basic.

◦ Optical grade clear polycarbonate pellets are fed into an injection-molder which creates a clear CD/DVD disc in its finished size and shape.

◦ During the creation of the clear disc, the injection-mold forces the molten polycarbonate up against the 'stamper' which embeds the pits and lands into the clear plastic.

◦ An automated process using robotic arms with vacuum suction cups transfer the clear discs onto a conveyor line where they cool.

Phase 3: Metalizing and Lacquering

◦ The conveyor line carries the clear discs to be 'metalized' with a very thin layer of reflective aluminum (the laser light from your CD/DVD player reflects off the aluminum layer to read the pits and lands that were embedded into the plastic in the injection-molding process).

◦ For CD replication, after being metalized the disc is placed in a spin-coater which spreads a UV curable clear lacquer evenly across the newly metalized layer.

◦ Not only does the lacquer protect the metalized layer but it also provides a good surface for the printing of the disc graphics by either Silkscreen printing or CMYK Offset printing.

◦ For DVD5 replication, instead of having a clear lacquer coat, an additional clear DVD disc is adhered on top of the metalized layer with a bonding agent. This additional clear disc provides the surface for the printing of the disc graphics.

◦ To cure the lacquer (or bonding agent) the disc is automatically placed under a high intensity Xenon lamp.

◦ After the lacquer (or bonding agent) has passed through the curing station the discs are automatically unloaded from the replication line and stacked on spindles with a count of 150 discs per spindle.

◦ From there the discs are taken to the CD DVD disc printing department.