Over at allposters.com, they have a framing option for posters called a mounted frame. This process is where the poster is spray glued on to 5/16 mdf hardboard, then a clear film is adhered to the poster itself, so protect the poster and give the frame a finished look. However, this process sans poster can easily cost $100 framed.
I only have about $20-30 so I made my own version. Home Depot carries a variety of 24x36 and 36x48 mdf hardboard so I simply measured my posters and had them cut the mdf to size. I painted the edges black and I spray glued the posters. I don't have the protective film but since I'm building it on-site it wouldn't be necessary.
Here's the front
And here's the back
Now onto the lobby. Removing it from my son's room since he longer has the space or interest in it, I took this stormtrooper and strengthened it with leftover mdf hardboard. I'll probably adding some backlighting for a glowing effect like my darth vader but right now it looks fine.
Front
Back
The star wars poster is a clearance from bed bath beyond but it was severely bowing so I had no choice but to drill it into the wall on all corners to make it flat. It was cheap so really no worries. I'm probably going to paint the wall for added impact but other than a few knick knack accessories the lobby is pretty much done
Victor