Doing this can give your photos a very distorted look that you thought they actually move!
Add a little spin to your pictures with this technique!
What you do is you take a roll of till receipt paper and draw swirls on it with a brush and some black ink. Then you take a 120 roll film, unwind it completely, glue the strip of paper onto the beginning and the end of the film and roll the whole thing back. Then shoot.
I use a Seagull for that, as I need at least three stops down for the light to go through the paper. The good thing is that the paper is nearly the right width of 120 film!