This colourful pattern was created using a found object, a metal thing with a shaped hole in it. The same pattern was altered digitally, below.
Rolling Stamps 59-61
This one is made from fun foam
this one from a small piece of table protector
and this one is just cling film
I had an article in Cloth, Paper Scissors about making rolling stamps a couple of years ago. The article is now available as a free download from CPS available here