A sheet of 4'x8' mdf (medium density fiber) board runs about $25-$30. The great thing about mdf is that you can mount murals, posters, wall paper, or specialty paper. And if you get the 3/8" thick "wow" you can paint the profile (the sides) and it looks so edgy.
If you search the web for wallpaper you can buy all kinds of samples. Here I made 'Feature MDF Boards' out of some samples and tried to keep the colors monochromatic.
I actually used this idea for a resturant that I decorated. All the images came from art.com. Most posters run about 24"x36" so I was able to mounted anywhere between 3 to 4 posters on one sheet of mdf for a fraction of what it would cost to frame just one.
I used the thinner 1/4 inch mdf for these two projects. I really like the thicker 3/8" way better though. But, for this project I didn't want the weight of the thicker board.
Originally these smaller boards were going to be used to display necklaces and earrings, but I just couldn't bring myself to putting holes in the boards (even though I was going to use a sassy glass knob). So I displayed them in hurricane lanters in clusters of three and used them as a backdrop for a table top installation.
Use heavy to medium wall paper paste when mounting on mdf. It takes a little bit of practice to get the feel of how the paste works on the board with posters or paper so start with something small like these little boards if you've never worked with wallpaper paste. The wallpaper paste works so evenly. That's why I like it and use it. Plus you'll get alot of milage out of a bucket of paste if your doing a big project.
You will need to make sure that your boards get cut straight. If you buy your boards at The Home Depot they will cut it for you very inexpensively.
Also, if you paint the sheet of mdf and mount it straight on your wall it gives such a dynamic impact. Dark grey chalkboard paint on mdf then mounted on cinder block, brick, stucco, or even drywall, looks so stunning! You get alot of bang for your buck with this product.
Are you looking for an idea for a teen room or your first home or apartment, game room,etc... and your on a budget? This is a great way to display trendy posters, childrens art, a newspaper article, etc... Remeber to think outside of the box. Just because a poster is 24"x36" does not mean you have to cut your board that size.
Check out the "Rolls Royce" of all wood board. I LOVE iconic panels!