Danish architect Jorgen Moller invented a product called a Posterhanger. A Posterhanger is actually a set of hardware that allows you to hang a poster on a wall without putting holes in the poster. Each set consists of two aluminium bars with rubber endcaps, six plastic clips and one nail. You can buy the sets with silver or black anodised aluminium tubes. In addition to posters, you can use the hangers to mount prints, textile wall hangings and other unframed pieces. Posterhanger sets are much less expensive than frames would be, for the size of artwork mounted.
Measure the width of your poster and procure a Posterhanger set for the size of poster you have.
Slide a long plastic clip from the Posterhanger set onto the middle of the top edge of your poster. Slide another clip onto the top right corner and a third onto the top left corner.
Repeat Step 2 for the bottom edge of the poster. Now you should have three evenly spaced clips on the top and bottom of the poster.
Select the top aluminium tube. It is the one with a small hole in the middle. Turn this tube so that it is parallel with the top edge of the poster and the hole is in the back. The slot should be facing downward.
Place the left end of the tube near the top right corner of the poster. Slide the tube to the left over the clip on that corner so that the poster slides into the slot in the tube.
Continue sliding the tube along the top edge of the poster until all three clips are inside the tube and the poster sticks out of the slot. Place an endcap on each end of the tube.
Slide the other tube over the clips on the bottom of the poster in a similar manner. Place an endcap on each end of this tube. Now you should have a tube secured on the top and bottom of your poster.
Hammer a nail into the wall where you wish your poster to hang. Slide the top tube of the Posterhanger onto the nail at the small hole in back. The Posterhanger is designed to balance the poster so it will hang straight.
Posterhanger sets range in size from 12 to 72 inches, allowing you to hang a wide range of artwork sizes. Make sure the tubes are a little wider than your poster so that the endcaps do not wrinkle the corners. If the white plastic clips lose their grip, replace them with small bulldog clips from an office supply store. Space them evenly across the poster’s edges and remove the wire handles of the bulldog clips with pliers. Use as many as necessary to securely hang the poster.