1968 Topps Clemente question
 

I bought a 1968 Topps #150 Clemente awhile back and it was nice but looked as if it had a surface abrasion on the back.

I just bought a PSA 6 that has the same apparent abrasion in the the exact same location on the back.

I started checking and found a small amount of cards on VCP that has the same apparent defect. It must be a lack of print. Is this a known print variation?

This is an example of a recent PSA 7 sold on EBAY:

https://www.ebay.com/itm/32493162759...p2047675.l2557

I’ve seen a few of them, thought they were abrasions at first because print errors don’t usually look quite like this. I think there is also a third version where the yellow is there correctly but a little lighter in color than the rest of the back. I’ve never picked one up but have it flagged on my spreadsheet as a possible RPD.