I've used wrapping paper to wrap my textbooks -- it just doesn't last long and has to be redone now and then -- and kraft-type paper on a roll is very similar to paper bags. (It's been a while since I've seen kraft paper gift wrap, but it might be available in a craft store.)
I know this is probably too late, but you can buy brown paper the same consistency as paper bags, even a little heavier on a roll at places like offices stores, Target or Walmart. I know because I have a big roll I used to wrap boxes to ship to people. Maybe you can get a roll for next semester! It looks like the long gift wrap or Christmas wrap rolls only it is heavy brown paper and found where they have pens and paper and such in stores like Target and I would just ask someone at an office store.