I'm having a devil of a time with getting chemical transference on my silver gelatin prints in the upper corner where I grab them to move them from tray to tray. If I use the old el-cheapo bamboo tongs with the rubber tips, or if I wear nitrile gloves and even wash the gloves between print batches, sooner or later I get an ugly purple blotch in the corner of the paper. Does anyone have suggestions for how to deal with this, and do they have any preferences for types of paper tongs?