Packaging paper as wall paper?

On some home improvement show(not this one...oops) I saw the hosts make wall paper out of brown packaging paper. It was tore into pieces and then dipped in a varnish and water mixture. It looked great! Do you now how much water to mix with the varnish? When the wet paper is placed on the wall are you supposed to smooth it out all the way? When it dries, does it shrink and would it pull away from a given spot(like a straight line at mid wall)? Please Help.
Thanks,
Tara