Disclaimer: I got this idea from Pinterest, so I am not claiming it to be my own.
Rather than search all over town I simply went to ebay to find the purple paper bags. Yes, "Backpack" is not this dark but I can't complain. The paper bags themselves actually came from Oriental Trading, which I felt kind of silly for not thinking of that in the first place. Next time, I guess. The face is not hard to draw so I copied it in pencil and drew over it in marker. I made color copies on my printer (I colored the mouths to save on printer ink), and--now the tedious part--cut out the pieces and glued them together on each bag. It's something to do while I watch reruns of Frasier after the kids are in bed, so it's not too bad. :)