How are DVD's and CD's made?

Is it true that CDs/DVDs last longer if they're kept in vertical wallets?

• An advert is making this claim - but I doubt it, because since I began putting CDs/DVDs into wallets, I have found more and more discs becoming unplayable. And in many cases it's not because of any scratches or other marks but because of some invisible defect. (And just to clarify, I'm not talking about recordable discs but proper silver factory-made discs). So is there any evidence that wallets are in fact damaging discs?

• Answer:

  It sounds to me like you are the evidence. CDs and DVDs kept in their original containers should be OK for decades. Since they were invented I've never heard of a properly used and stored CD or DVD failing. Until now the worst way to treat them that I had heard of was these holders that you put on the sun visor. On bright days you can just see them warping from the heat. But it sounds like this wallet is adding minute scratches. But it is known that any time that you slide a CD or DVD along one surface you will start to get tiny scratches.