I was in a hurry before I went to NZ earlier, and my film pusher didn't have a proper changing tent. So I bought a Paterson changing bag. Looks OK, with tight double sealed holes for your arms and a velcro flap over the zipper. Enough room to load 4x5 holders.

However, after having my arms in there for about a minute, they start sweating.
After one or two holders my hands are wet.

One or two of my negs from this trip has visible fingermarks - do you think that my sweaty hands in the changing bag could do that?