I cut two pieces of medium PG leather last night with PG settings. both on separate sheets of PG. both times, I found it very difficult to begin to peel off the masking. once it got started, it peeled off relatively easily. but both times it seemed like the edges of the masking had, for lack of a better word, fused to the leather surface where the burn had happened. it took some very careful prying with a fine pair of tweezers to get it to start peeling in both cases.
i haven’t had problems with masking on any other material. nor did i have any problem with the medium tack masking i applied to my own non-PG leather.