Of course there is a myriad of excellent renditions of the Innsmouthians out there, done by wonderfully talented artists, but I have a small grievance: The majority of such work I have seen has been placed a bit too late in the metamorphic stage for my tastes. Just saying that if I can't slap a hat on the poor mutant and call it human, then I'll call it a monster and have my silly investigator raise the revolver.
For Game Keepers:
I print on photo paper and then apply a thin layer of shellac varnish. Usually, this makes the pictures a bit more hardy for use and give them a rustic found-in-ancient-damp-cellar kind of vibe.