Media type that can be recorded and re-recorded by end users with a storage capacity of 650 MB, bringing the same level of convenience as floppy disks. Also called CD-E (CD Erasable). CD-RW recording is done through a CD-RW recorder, also known as "CD-RW burner".
The disc is manufactured using a photosensitive material that changes its chemical and physical characteristics accordingly to the temperature. This technology is called phase-change.
CD-RW discs have six layers: the phase-change material uses four layers, on top of them we have a plastic substrate layer and then a lacquer layer. The photosensitive material is made of four chemical elements: silver, antimony, tellurium and indium. The fusion temperature for liquid state is around 600º C and fusion temperature for solid state is around 200º C.
On a CD-RW, the pits and lands found on a regular CD are represented with the physical state of the organic material:
Solid state = translucid = lands
Liquid state = opaque = pits
Since the recording and erasing processes of CD-RW are done using heat, you should avoid letting your discs face light and heat sources, like the sunlight.
In order to read CD-RW discs, CD-ROM units must have a circuit called AGC (Automatic Gain Control). Older CD-ROM units don’t have this circuit, thus they cannot read CD-RW media. This happens because the reflection ratio (the amount of laser light that bounces reflects back after hitting a reflecting point) of CD-RW media is far lower than commercial CDs (“silver” CDs) and CD-R. While commercial CDs have a reflection ratio of 70% and CD-R 65%, on CD-RW only 20% of the laser light reflects back when it strikes a reflection point.
