This is a mounting technique for when you just want to temporarily mount and image for transport and casual display, but not frame. Assuming you are printing the image yourself, leave about a 1 inch white paper border around the image. Use photo corners to mount it to foamcore that is little larger than the image and then shrinkwrap the entire package. The photo corners will keep the image centered on the foamcore and the shinkwrap will keep it from bowing out of the photo corners and protect it from finger prints. If the foamcore is larger than the paper, minor dings should only hurt the foamcore and not the image.