At your next show you want to make sure all your paper prints are easily stored and protected. If you are offering your prints for sale you may want your potential buyers to pickup, handle the print and be able to look closely at the details. If you are not properly protecting that print, over a short period of time it is easy to damage the print. A potential buyer could drop it, spill something on it, etc.
With paper prints I think the best way to protect them and still let the customer handle and view them is with a plastic sleeve and corrugated sheet (cardboard). The process is very simple. Place your print in the plastic sleeve, seal it and tape it to the sheet of cardboard. This way when a person is handling the print and they accidentally drop it, the edges of the cardboard are damaged and not the edges of print itself.
As for cardboard, you can get them at Uline.com, usually in batches of 50 or 100 for each size. They have a number of sizes you can choose from but I think if you are going to be offering a stack of prints for people to browse, stick to one size. It keeps things even and neat.
Yesterday we started to offer flat clear plastic bags for different size prints. The bags are archival quality meaning they are acid free and will not cause the print to breakdown over time. They are popular with comic book sellers, print sellers and others where preserving the quality of the contents over time is important.
When we initially started to stock those last week we intended to package all of our mounted prints in those however we realized a number of customers may want to purchase them on the side.
To provide that option we made available to ability for people to also purchase individual bags. There are various places you can buy these for your prints but from what I have found you can only buy them in bulk. Hopefully by offering them in singles it will be easy to select one or even a few on your next order.