I print my trail topos on National Geographic "adventure paper" that I got on sale at like 75% off. For all I know, it may be sourced from Rite in the Rain. But it seems to work. I've tested my topos by letting them dry thoroughly (overnight) then putting them underwater in the sink and scrunching them. There is a very slight amount of smudge here and there, but I would estimate the map remains 98% usable. I dunno how it works.