Best media for PSX "backups"?

[McPhreak]

I've got an old school PSX which has trouble reading some types of blank media (My Kodak Ultima Golds for instance). For any of you who also have an older PSX, can anyone tell me what sort of media they use to *ahem* "backup" their PSX games. I don't want to buy a 50 CD spindle and find out that they won't read. Thanks.