Here's a quick, easy and inexpensive way of mounting a poster in a permanent and clean-looking way. I bought this poster as a contrast to my 3D periodic table, and wanted to do Murray Robertson's great artwork justice as opposed to just pinning it to the wall. There are other descriptions of how to make plywood-backed posters, but the poster I got was thick and glossy and I was concerned that the mod podge approach might not be best suited to the my poster. So I used spray-on contact adhesive instead, and it worked well enough that I thought I'd share the process.
- poster. Make sure the poster is nice and flat. I left mine between two sheets of plywood overnight.
- spray adhesive. I used Super 77, but I assume any contact cement spray adhesive would work.
- plywood. Thicker and higher quality the better, for planarity and edge appearance, respectively. Cut to the size of the poster or slightly larger.
- a large sheet of paper. I stuck two pieces of brown butcher paper together with masking tape. The paper needs to be bigger than the poster.
- finish for the edges. I used Varathane water-soluble crystal clear finish.