A contemporary band recently released a CD without a reflective layer. My son asked me about ways it might be read. It looks completely clear but when tilted in the light you can see the rainbow of recorded material. I believe it's a data CD, not audio, as statements from the band hint it contains the MP3s of their previous four albums. (Why did the band do this? They said they were making an artistic statement about the nature of and longevity of CDs, and as a puzzle to their fans. The other half of the package was on a second CD in an uncommon format known as "Mini-Max", where it is an ordinary-sized CD but only the center 3" is silvered, giving it a distinctive look.) I asked a friend who was an engineer at a 3M pressing plant in 1986-88. He said that early CD-ROM drives could read a CD that didn't have a reflective layer. He thought these drives had some of the first Phillips and Sony mechanisms. He said they read discs like this "all the time" in the production process. He also thought there were a few "novelty" cealer discs produced this way in those early days. He thought that by today's standards, these first-gen readers had lasers that were overpowered and the gain circuitry more sensitive, so they were able to read the un-aluminumized pits in the pressed polycarbonate. I believe I first acquired a CD-ROM drive in 1988 or so. I may even still have it, but I've yet to hunt for it in my storage. I don't remember the brand of its internals. On eBay I see old Phillips CD reading mechanisms selling for astounding prices of more than $500, as they're used by equally astoundingly-priced ($3,000-5,000) high-end CD players such as the Studer brand. Bits is bits, you'd think, but as usual, not for the high-end audio enthusiast. http://www.thevintageknob.org/THEVAULT1/D730/D730.html The same mechanisms were used in the first CD-ROm readers for PCs such as the Phillips CM100. I believe this CD has its top-coat of acrylic / lacquer. I think that adding a reflective layer at this point (such a shiny paint) wouldn't affect the readability of the pits (and that spray-paint would probably melt the lacquer.) As I understand it, the depth of the pits are about a fifth of the wavelength of the light used to read them, so the detector sees a phase shift. Does anyone remember if first-gen CD drives had such super-powers? Does anyone remember any clear pressed CDs? Any advice on how this clear CD might be read? - John