That's what I was thinking. I believe there are two basic types of dye used, but beyond that I know little. You know, I buy quite a few DL BD50 blu ray & DL DVD discs. A lot of what you find is pure shit. You can play it safe and buy Verbatim or Genuine anything made in Japan and you're mostly OK, although I get the occasional coaster even with Verbatim...but they cost. I always have to weigh coasters in one hand and cash in the other and decide what's it gonna be? With some brands of DL50 GB BD's I might get 10 coasters out of 25 discs, but only pay about 35 dollars. Verbatim I can get decent ones for about 65 dollars for 25 discs and MAYBE get 2 coasters. I always burn at half speed with my LG BD burner, except maybe the occasional DTS CD backup. I have found some reliable DVD DL discs I'm happy to say that are a bit cheaper than Verbatim. (jeez another book I'm writing)