This was originally printed in PLA, but it can be split in the slicer so you can use TPU for the stamp face. It prints well with either the stamp facing down, or with it facing up with ironing on.

When made with PLA, you will need to use a fair bit of force to create an imprint, so plan your print accordingly.

Elegoo PLA - Black
0.4mm nozzle
0.2mm layer height
3 perimeters
0.6mm minimum top and bottom shells

I used 15% Lightning infill, but any infill will likely work.