What kind of folder can I use to put my traditional art in?

I use a bunch of mediums for my traditional art. I'm looking for a folder that I can safely store my art in without it getting all smeared/smudged. Also, the paper I use isn't standard letter size, it's an inch or so larger. Any suggestions on what to put my art in? (I tried those enclosed yellow packets already, with the clasp, and they were too small.) I don't want my art sticking out... after all, the folder is so that my art is protected.