Ok, time to bump this thread…
Just bought one of my long time ISOs, EMEK's 2005 Nine Inch Nails / QotSA Calgary gig print. I was told it was in mint shape, and when I received it, I discovered a bunch of scuffs throughout the black areas of the print. See below:
I contacted the seller and he suggested I try a trick to get the scuffs out, and if it doesn't work, he will refund me in full. So what's this special trick you ask? Well, wash your hands clean. Dry your hands. Pour some water in a cup. Take the tip of your index finger and get it slightly wet (a thin layer only), and dab the scuff gently until the water evaporates.
Low and behold, this worked perfectly! No shine, and the water didn't bleed through the print.