Black marks on balls
I had the same issue with my new Diamond Pro table. The diamond guy said it was the die of the black leather coming off and he did not know how to stop it.
Then I talked with Glen (Realkingcobra on AZ) . In my opinion, the best table mechanic in the country.
He suggested to use Kiwi black shoe polish on the pockets. Then use mink oil or saddle soap.
I did both and my new Brunswick Centenial Balls are markless.
Let me know if it works for you. And give a special thanks to Glen.
Best Regards,
Hal in Ohio