[monkeylove]

What I sometimes do is get the media identification code:

https://en.wikipedia.org/wiki/Media_Identification_Code

using a program called DVD Identifier for Windows:

https://www.videohelp.com/software/DVD-Identifier

to find the manufacturer of blank disks, and then look for details on them here:

http://www.digitalfaq.com/reviews/dvd-media.htm

https://www.videohelp.com/dvdmedia