I have a wonderful book of pictures from dog shows in the 1920s and '30s and would love to make them one wall of a bathroom. Method-wise, I'm just guessing. I know you can use or make your own paste, but do the photos (on slick stock) need to be used as they are, or, should they be scanned onto a different paper; and, should some type of protective material be used to preserve the paper/photos from water, dirt, etc.?