This is an irreversible chemical process. The dye is typically a blue color, but when a gold reflective backing is applied, it appears green. When silver reflective backing is used, it retains its blue color. Phthalocyanine dye tends to be a lighter blue than cyanine, and phthalocyanine disks have a life expectancy of 100 years, whereas cyanine life expectancy is 20 years. This phase change can be reversed to make the area erasable and reusable.
Some media is designed to be thermal printable and some ink jet printable.
CD-RW can be erased and reused. If you have a recorder that does both cd recording and cd rewriting, we recommend you use cd-r media for all music and most other purposes. The jewel cases increase the cost of shipping the media - disks in jewel cases weigh three to four times more. If you are, for example, developing a software product that you will be distributing in sleeves and do not need jewel cases, you can purchase media a on a spindle. A spindle is a dowel, sometimes on a base, on which 100 or more cd-r disks are stacked.