Would it be wrong of me to use good, old Kraft paper to cover the back of my frames instead of acid-free frame backing paper? I already process my prints using archival techniques and use conservation type dry mount tissue, foam board, and mat board. I don't foresee my photographs hanging in any museum (except my own). For me taking the picture, making the print, and framing it myself is a hobby. I do occasionally give away framed prints to friends, and I can see one day selling a framed print or two to those willing to pay (not my raison d'etre). I do worry that the prints will last for them.