Large prints can be heavy to hang and expensive to frame. Here's a tip that'll save you some cash while showing off your beautiful print.
Glass Has 2 Disadvantages
First of all, it's heavy. I don't know about you but the thought of busting out the wall anchors, level and power tools just to hang a print seems like a lot of effort to me. That, plus the risk of the frame falling and shattering all over your floor is enough to give me anxiety (very possible with my two young sons running around). Going with plexiglass is a good alternative but it can be even more expensive than glass when you need a big piece.
Second, glass creates a glare. You can spring for the non-glare version at your frame shop but, let's face it, if you're trying to frame your art on a budget, it just isn't in the cards.
Now, I'm not one to spend hundreds of dollars on framing my prints...I like to change them out too often to invest in any kind of expensive, breakable solutions so I found a way around it.
The Old Days
When I was in photography school at SCAD, we used to print, mat and frame all our own work. One of the things we used to do was dry mount our prints onto a foam board before we presented them for critique. This basically glued the print to the board, creating a rigid image that was easier to frame or hang. The process involves using a heat activated adhesive film and a press which melts the film and adheres the photo to the board.
Here's The Trick
For larger prints I take them down to Michael's (or your local frame shop) and for about $25 they'll dry mount your print to a piece of 1/4 in foam board. You can then just pop it right into your frame, no glass needed. This actually looks really nice when your print is on glossy paper...gives just the right amount of glare so it almost seems like there is glass but without all the weight.
A Few Words Of Caution
1) Make sure your frame has enough room to fit the 1/4 inch board inside the lip or the backing won't close. Some frames have very shallow depth (the area where the glass, print and backing sit) and you could end up with a print that doesn't fit your new frame. If your frame has a shallow depth, see if they can use a thinner board...maybe a mat board or an 1/8 inch foam board to be safe.
2) Be sure to call Michael's (or your local frame shop) to check that their heat sealer can accommodate the size print you have. I believe Michael's can do up to a 30x40" but it may vary from store to store so make sure you call first.