The handle has a flange that snaps into the recess on the back of the stamp.  It works well with a standard felt ink pad, but should work with a variety of paints, including acrylic, oil, and watercolors. There is an alignment triangle on the handle and notch on the stamp to help line them up when stamping on your paper.

The .step file for the blank stamp is included. Just import it into your CAD software of choice and draw your desired stamp on the flat surface. I recommend extruding the design 1.5 mm.

Print the stamps of your choosing with TPU using 25% Gyroid infill. This gives the stamp plenty of flex, allowing it to conform to a less than flat surface. Place the stamp with the mounting hole facing the build plate. Use minimal support.

Print the stamp handle with a non flex filament with 10-25% infill. Place the handle with the flange side toward the build plate and use good support settings. If you print with a “fuzzy skin” setting, it give the handle a good amount of grip.