These are unmounted rubber stamps and I don't mount them. the foam in the stamper's friend or Misti have enough give. If you don't have a stamping tool, you can still use them unmounted, just put some craftfoam or a mousepad underneath your paper.
I had started with the "tentacle" flowers in black, was too stark, then I made a mask for the snail and stamped the flowers behind him in grey, still didn't like it.
Then I fuzzy cut the snail as I had stamped him on the Crafter's companion Neenah paper and I already had wasted one panel.
Mounted the happy birthday panel with foam tape and part of the snail too and his body I mounted with tape runner.