How do you know its from the disc? Do you have white rubber everywhere else in the game?

The disc rubber is thin and grippy and doesn't really shed itself on your playfield....

Maybe Stern had a shitty batch of rubbers or something. Either way, swap all the playfield rubber to white. It will play faster and stay cleaner (note there is also 4 rubbers and 4 rubber nubs under the disc plastic so make sure you replace those too (you should be able to work around the recognizer and get the nuts off without having to take off the ramps completely e.t.c.)

Mine did the same thing. I tried switching to white and no improvement.

Changed the rubber and acrylic platter on the disk and reduced the marks by 90%.

Getting the rubber off the acrylic is near impossible. Get the acrylic platter and its and easy change.

Don't forget all the black rubber posts. Change them to the colored Cliffy replacements.

Stern is known for using bad flipper rubber that breaks away easily. Not sure about the others though, inspect your flippers.

I cleaned my disc with the pin guard rubber cleaner from pinballlife and that helped a lot with the black marks I was getting on the play field.

I have seen this on another Tron as well but not sure why it happened. Mine is an LE and hasn't done this ever, but I know of a pro that had this problem really bad. I think it was the disc because the rubbers were changed to white and the black marks would still show up everywhere.

Mine does it bad. Had mine about two weeks now. Got the pinhuard rubber cleaner and have cleaned disc three times...and play field like 6 times. Those black marks bug the hell outa me!! Such a beautiful machine, and within three plays...the pf has 30 little marks. Grrr