Poster holder

Small poster holder using rolling pin wedge principle, so we have gravity working for us.
After printing wiggle the roller a bit so breaks free and is able to roll freely inside the housing.
I used the tip of a ballpoint pen to nudge the roller free.
For mounting I used some generic tack putty. Let me know if you want me to design a version with holes for nails or pins.
Do not use supports!
(also ignore the giant creases on my poster. It was used to test the viability of my design :P )
Update: added a version with bumps on the inside for those people who are having trouble getting the roller to grip properly.