Today I bought some Imation Professional Grade CD-R’s to try out.
They’re manufactuered by CMC Magnetics Corporation (97:26:66) and have a very unusual serial number on the central plastic hub that is printed horizontally instead of curving with the shape of the disc as normal.
DON’T BUY THESE! In my tests, the average C1 count is over 10 and max C1 is 60. To be fair to these discs though, there were no C2’s recorded. Still far from professional grade though!