Recurring print defect in the right border.
1973 Topps - [Base] #596 - High # - Boston Red Sox Team
Courtesy of COMC.com
And this one, mentioned by a blowout user, is the recurring print line at the top of the image.
1960 Topps - [Base] #350 - Mickey Mantle [PSA*7*NM]
Courtesy of COMC.com