A custom fragile-decal roller stamp I made to quickly add markings to packages (the postal service is really rough with packages here).

The outer roller has a tight fit and internal nub, it is intended to be printed in a flexible material and pushed onto the spindle.

Material notes: The spindle and handle can be anything firm, pla or petg ideally. I tried TPU first for the roll, but it was too slippery for my particular ink to stick. You could try PLA or TPE; I ended up printing it out of Siraya Tenacious resin with 24% infill and 1mm wall, after a light sanding the ink is sticking decently. For high detail, resin prints are recommended if you have an SLA printer.

Print Notes: Print slow and accurate, you want the outer surface to be as flat as possible to evenly apply ink. Fast printing leads to very small overshoots which will result in only the corners of the text contacting the page X3
Sand the roll if its uneven or seems to apply ink spotty

I included the .blend file in the zip for anyone who wants to try customizing the decal. Just turn off the deform modifier on the blank roller and model your custom decal, boolean it on flat or after both objects are deformed to a loop. Remember to mirror either your decal or the entire roll after boolean, or your decal will stamp on backwards :p