Stores often roll posters tightly into a small tube to allow for better storage of more items in a small space. Upon purchasing the poster and opening the poster roll, it can quickly become evident that the poster has set in this position for a great length of time. In order to hang the poster without having any curled edges, the poster needs to be straightened out prior to hanging.
Roll up the poster in the direction opposite the one it was originally rolled in. For example, if you place the poster on a flat surface and it curls up to show the poster face, curl the poster the opposite direction so that the back of the poster is on the outside.
Place a rubber band securely at each end of the poster. Allow the poster to set in this position for one to two hours. Remove the rubber bands once the poster has set for some time.
Unroll the poster and place it on a flat surface. Place one weighted item at each corner, and one item directly in the center. Items such as small weights, books, or blocks are reliable weights to straighten out a poster. Allow the weights to set on the poster for two to four hours. Remove the weights and hang or frame the poster as desired.