The absolute width limit is 48" (1.2 m). We suggest that you prepare a poster no taller than 36" (0.91 m). That said, taller posters will probably work (see below).

Posters will be placed on posterboards and presented using easels. While we plan to provide an abundance of push-pins, it is always prudent to bring a few of your own and affix the poster securely, with the posterboard placed on the floor. 

The posterboards come in two sizes: a tri-fold of 48" x 48" and a semirigid 36" x 48" (H x W). We have more of the trifold sort, which can of course accommodate taller posters. Experiments with the semirigid kind indicate that a poster that is 40 in high should be okay. If for some reason you require the extra real estate, plan to put up your poster early so you can make sure to have a trifold.