So I wanted a stamp for work that would allow me to write a message faster (why else do you want a stamp). I didn't have any TPE (rubber like filament) so tried a convex lettering that you can roll with PLA (a solid plastic the same as disposable cutlery)... Works a treat. Bigger top to bottom works better as it gives a more even spread if your hand goes off at an angle when rolling it. It did require a little sanding to get good results. The flat version I did first was good on flat paper but as soon as there was any angle it went off. Also don't forget to make it a reflection ;) I picked up the ink pad at a craft shop for $6 so still way cheaper than anything purchased.