Unroll the poster and lie if flat on a hard surface. Place books or other weights onto the four corners of the poster and allow it to remain overnight. This ensures the poster does not curl.
Choose the area for the poster. Wash the area with soapy water or a cotton ball soaked with rubbing alcohol.
Pull away four, dime-sized portions of the poster putty. Roll the individual chunks of poster putty in your hands to form them into balls.
Turn the poster over and press one ball of the putty onto each corner of the poster. Center the poster onto the wall and apply gentle pressure to the putty to keep it on the wall.
Step back and examine the poster. If it is not level, gently pull away the poster and putty from the wall and adjust until it is level.