I don't know if any of you watch the television show "Lockup" on MSNBC (it's an ongoing documentary series on prison/jail life at various penal institutions around the U.S., and, occasionally, other countries), but, I always think its neat when they show some of the things that inmates are able to fashion out of paper.  I've seen typical PM models/sculptures (a rather disturbing-looking clown gripping two big knives in his fists that one inmate made as a gift for another immediately comes to mind), dice for gaming/gambling, etc.  So far as I can tell, they seem to make these items out of compressed toilet paper, which I assume they wet, to make it more malleable while they shape it, and then let air dry (I don't imagine they'd be allowed to have any kind of adhesive in their cells, although I could be wrong - I suppose one could probably use various food items/ingredients as a binding agent in a pinch.)  Of course, there's also a darker side to things, as some inmates will use paper to fashion crude weapons to use against one another or the guards [improvised spears/shivs formed from paper tightly rolled up and sharpened into a point, paper crossbows (with elastic from underwear/socks for the string), etc.] I've never been to prison, and, hopefully, never will, but, if such misfortune should ever befall me, I could see myself whiling away the years making an army of little toilet paper monsters in my cell . . .

It's not papier mache, but I also remember one other episode, in a women's jail, where one inmate was making improvised markers, out of tampons, for use in decorating the cards she was making for her mother and child.  When it comes to art, humans always find a way to express themselves!