Things You'll Need
Instructions
Place the poster print-side down onto an acid-free cardboard backing. Labels on cardboard backing that say "acid-free at time of manufacture" are not truly acid-free and only have a protective layer that may come off in time. Look for cardboard packaging that simply says "acid-free" and shows a minimum pH of 8.5.
Slide the poster on the cardboard backing into a Mylar poster sleeve until it is all the way at the bottom.
Fold over the top of the Mylar sleeve and seal it closed with small pieces of clear tape.
Place the boarded and covered poster on a flat horizontal surface in a cool, dark and dry area. Do not stack more than five posters on top of each other.