Crazy. I guess the ink dries fast enough and sprays with enough velocity that it doesn't matter?
the douthitt wax is heated to 105 and then essentially shot onto the screen and
dries cools immediately so it sticks to the screen.
Same as the ink it dissolves in water.
As far as the rollers, id' say weight and the issue with the corners sticking up keeps them off the show floor.
for show purposes it's easier to demonstrate something that is grab and go.