My daughters and I created shapes with FIMO polymer clay to use as stamps. To make the swirls, I rolled small amounts of softened FIMO into snakes and pressed them lightly onto a square of FIMO I'd flattened with a rolling pin. My daughter made the black dotted stamp with a slotted metal spoon and I curled it so that it could be rolled while stamping.
After baking and testing on various surfaces, results were mixed. The photo above shows the stamps on watercolor paper. Stamping ink was not thick enough, so I used Golden fluid acrylics. Results were clearer using fabric or a paper towell because more of the stamp made contact. On paper, the black dotted stamp worked best - when it rolled, all of the dots touched the paper. The smaller swirl was not flat so part didn't contact the paper. The swirl on the square backing works fairly well. The rectangular stamp made small rectangular patches.