Duplication versus Replication for CD

Understanding the differences is important in determining which process is best for your project. A duplicated CD is not only created using a different process than a replicated CD, but the actual final product is also different.

There are two ways to make a copy of a CD. Information can be burned on to a blank CD-R; this method is called duplication. Information can also is added during the CD manufacturing process; this method is referred to as replication.

Understanding the differences is important in determining which process is best for your project. A duplicated CD is not only created using a different process than a replicated CD, but the actual final product is also different. After the duplication process is complete, the final product is a CD-R. Replication stampers for CDs produce CD-ROMs. (ROM means Read Only Memory).

The Processes

CD duplication is similar to burning a CD on your personal computer. A CD duplicator extracts data from the master disc and writes it to a blank disc. The difference between burning multiple CD-Rs at a duplication facility and burning one on your computer desktop is that the duplication facility burns hundreds at a time on towers that are linked together. Each tower contains several CD trays so that many copies can be created simultaneously. After all the data has been written unto the blank CD-R, the information is verified with the master, and the process is complete.

CD replicates, on the other hand, are created during the manufacturing process. In other words, media like a CD-R does not exist before the process starts. Before the replication process gets underway, the client master is painstakingly evaluated for data corruption. Then, a glass master containing relevant data from client supplied master is created. Replication begins when a flawless glass master is assured. The glass master is used to develop a stamper. The stamper, in turn, is loaded into an Injection Molding machine that creates CD replicates. The quality of CD replication hinges upon the quality of the glass master's data. Through each successive step, quality and accuracy is consistently monitored to insure each disc is an exact replica or clone of the original. A layer of micro-thin aluminum is applied to the polycarbonate disc. It is then lacquered for additional protection and printed before packaging.