You can modify the stamp width and choose the handle profile you'd like on OnShape.

By default there's a 25mm wide and 50mm long variant, and then from there, there's a 55mm, 75mm, and 100mm long variant.

You can customize what is actually on the stamp by embossing text or an SVG in your slicer (see below). Make sure to position anything you want to show up on your stamp between the alignment bumps. I found a height of 1.5mm is just about right.

And make sure to set the emboss to be reversed so that it looks backwards in the preview:

or

Feel free to print the handle part in whatever sturdy plastic you'd like (PLA, PETG, ABS, ASA, etc). Use 4 wall loops.
Print the stamp part in TPU. Use 4 wall loops and 100% infill.

The author marked this model as their own original creation.