Much like Gobbler, my thoughts are also that of time.
DGrum mentioned the lack of interference from the many things that could best be described as distractions.
Such engravings demand time, lots of time, and for the person who can dedicate the required amount of time into such engravings, while avoiding the majority of modern day distractions, then my hat is off to that person, and I do hope you are that person.
Respectfully, Russ...