OK, stupid noobie question. I've been new to the PT printing scene and have been seeing a lot of "gum over this and that" prints. In dummy language, what does the "gum over ..." do exactly to my platinum print? Can I gum over my platinum prints? In one of the print exchanges, I received a gum over something print (which was gorgeous) and I believe it was tri-coloured. So I thought "Does the gum-over thing add more colours?" Then I bought a print from Michael Mutmansky that was a gum over palladium print (and it too is gorgeous) but it was only one colour. So I don't know what the gum over thing does anymore. Someone please explain. Thanks in advance, Art.