don't do this kids, the delta p, or difference in pressure, from a water pump is insane and will easily rip your arm off if you're lucky or get you stuck and drown you if you aren't.
@Matjan it's not about the physical matter but how it was used. The rolling stamp was use as an identifier and proof of power, but the Greek stamp was used in a controlled way to convey information, similar to how the movable type is a huge step up from a printing plate.