Why can't you cut my CD-R's?

Without a doubt the most common question (and one of the hardest to explain over the phone) is the difference between a CD and a recordable CD (CD-R), and why we can't cut the CD-R discs you buy from your local electronics store.  Let's look at how CD's and CD-R discs are made.

Fine, how do they make a CD?

CD's, whether they are audio discs or CD-ROMs, are manufactured the same way.  A stamper is made that imprints the data on the top side of a polycarbonate disc when the disc is molded.  A reflective layer is then sputtered onto the top side of the disc to bounce the laser back to the reading components of the drive.  The lacquer coat is spun over the metal to protect the aluminum from oxidizing, scratching, or other damage.  Silkscreening or offset printing goes on top of the lacquer coat.  The entire process of manufacturing a compact disc in this method is called REPLICATION.  Replicated discs are quite durable and are able to be cut.

Cross Section of a REPLICATED CD

Then how do they make a CD-R?

Recordable CD's, or CD-R discs, are different.  On a CD-R, the polycarbonate disc is molded with a blank track.  A dye layer is spun over this that will react with the write laser of your CD-R drive to put your data on the disc.  The reflective metal layer is then sputtered on top of the dye layer to provide a surface for the laser to bounce off of.  The lacquer coat provides the "glue" that keeps the whole thing from falling apart.  The process of burning data onto CD-R discs is called DUPLICATION.  Whether it is one CD-R or 1,000, it is still DUPLlCATION.  A "normal" CD-R will hold 650MB of information (or more).  Below is a cross section of a CD-R. 

Cross Section of a CD-R

Neat.  Why can't you cut them?

Cutting a disc doesn't exactly qualify as typical use.  As long as the lacquer coat is intact, the disc is will function fine and stay together.  As soon as the lacquer coat on a CD-R is pierced, however, the whole thing flakes apart.  This is due to the fact that the dye layer provides little or no adhesion for the reflective metal layer to remain attached to the polycarbonate disc.  The dye layer and reflective layer are masked, so that they do not extend within the mirror band/stacker ring area, and so that they are at least a millimeter from the edge of the disc.  The lacquer coat is spread pretty much over the entire disc, including over the outer edge.  When it is cured, it is the component that keeps the reflective layer from peeling off the top of the disc.  

The end result of all of this is that if we try to cut a normal CD-R, the disc will basically fall apart at some point in the process, making a tremendous mess.  This mess can be somewhat pretty if you hit a cut CD-R with compressed air (it looks like you are in the middle of a snow globe), but the disc won't work.

Isn't there ANY CD-R you can cut?

Yes, but they aren't aren't "normal CD-R discs".  Cuttable CD-R's are discs that have a dye layer that is masked off to where the disc will only hold 40-50MB.  We can cut these by just staying out of the way of the dye layer.  The rest of the disc outside of the dye layer is the same as a normal CD.  We do not currently stock these discs, but they are available from other sources.

UNCUTTABLE 650MB CD-R                  CUTTABLE 50MB CD-R

Most cuttable CD-R discs will hold 40-50MB.  If you are looking for discs that will hold more, you are looking for an expensive custom manufactured item with a long lead time.  Please feel free to contact us with any questions you might have.