During the process of engraving the message inscription on a tombstone, a process called sandblasting is used.
First a stencil with the message is cut out of special plastic tape with a paper backing using a vinyl cutting machine or plotter. This tape is called sandblast tape. The tape is the applied to the plain tombstone rock surface and the lettering removed from the stencil, exposing the rock surface in those parts.
The tombstone or gravestone is then sandblasted and thereafter the tape is removed. Leaving the surface around the lettering undamaged or changed. The exposed portions have been carefully blasted away leaving the imprint of lettering, which we see as the tombstone message or gravestone inscription.
This process is typically carried out by funeral parlours or tombstone companies.