I have seen many fingerprints, scratches, and specs of stray printing or molding materials that adhered to the underside of MAM-A Archival Gold discs over the last year. I visually inspect every disc prior to placing it in the burner. At one point I was so frustrated I contacted my MAM-A. Apparently I wasn't the only one complaining. And as of lately they have obviously stepped up their QC.
--Jeff