Permanent Markers on CDs

August 18, 2005
Using Permanent Ink Markers On CD's and DVD's...

The easiest way to label a CD-R is to whip out that permanent marker and write directly on the disc. It's also a great way to assure that the disc won't be readable later on.
The damage won't happen today, or even next month, but at some point the ink will leach into the reflective layer of the disc and it'll be the end of your data.
Now, we're not saying you can't label your discs. But you do have to be careful of the kind of writing instrument you use to do so. In order to understand why certain markers and pens can harm your CD-Rs and DVDs, we first need a basic lesson on the physical properties that make up the disc:
CD-Rs and DVDs are made mostly of polycarbonate substrate, or plastic. The plastic is there to carry the data layer - the shiny metal you can see when you look at the bottom of a disc. The data appear as marks or pits that either absorb light from the laser beam or transmit the light back to the laser/photosensor by way of the shiny metal reflective layer.
Most people know that it is very important to keep the bottom of your discs clean and scratch free. Scratches, fingerprints, and other debris can stop the laser from reading the data.
However, most people don't realize that the tops of discs are just as prone to damage as the bottom - if not more so! Although you can physically see the shiny data layer from the bottom of a CD-R, it is actually applied to the TOP side of the disc, just under the label. On some CD-Rs, the data layer is under nothing but a thin layer of lacquer. Damage to the top of the disc can destroy the data all together.
Read More HERE.