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Make sure your discs do not suffer a premature demise:

Accelerated aging tests show that your CD-Rs can last 100 years, CD-RWs will last about 25 years, and store-bought CDs will last anywhere between 20 and 100 years.

Your basic CD-R has several layers from top to bottom.

• Label (optional)
• Scratch-resistant or printable coating (optional)
• Top UV-cured lacquer coat
• Reflective metal layer (24K gold or a silver alloy)
• Organic polymer dye
• Polycarbonate substrate (the clear plastic part)

Slow down, buddy

A slab of polycarbonate (plastic) about a millimeter thick makes up the bottom of a CD. The layer is usually transparent, but some discs use tinted "black" materials to create a snazzy appearance.

At high rotational speeds (equal to reading at about 50x at the outside of a disc) the polycarbonate starts to deform. If a disc with mild defects spins near this speed, it can shatter.

Color can make a difference

The laser in a CD recorder leaves marks in a CD-R's organic dye that simulate the pits and lands of a pressed CD. CD-R manufacturers choose from three different types of dye, each of which has unique properties, including different life expectancies and slightly different colors. Changes in maximum recording speed may require alterations to the dye formulation. Some discs will work better with certain recorders than with others, which is why it is recommended experimenting with different CD-Rs before you buy in bulk.

Beware CD-eating fungus

Store-bought CDs and CD-RWs have an aluminum reflective layer, while CD-Rs use 24K gold or a silver alloy. Since the reflective layer should outlive the organic dye, most people shouldn't concern themselves with the choice. If you live in a part of the world where the dreaded CD-eating fungus lives, choose gold. Though slightly less reflective and more expensive than silver, gold doesn't corrode.

Scratch of death

The top layer of a CD-R is made of a coat of UV-cured lacquer that seals the disc and holds everything together. Don't scratch the top of the disc. Damage to the polycarbonate bottom layer can be fixed, but a small scratch on the top of the disc will expose the delicate reflective and dye layers, causing them to degrade rapidly.