They're hand-sanded during the build process. These damned earthlings never do anything the exact same way twice with their hands!
People say they love hand-made, individually produced stuff, but it isn't true.
They really want predictability and uniformity, and that's why they pay lip service to hand-made, but buy as much molded, stamped, machined and CNC stuff that needs no hand work as they can cram into their homes.
Never mind that most of it winds up in landfills.
PRS uses machines, too, of course, but then there's that inconvenient, hand-sanded, people-crafted finished product that we are forced against our will to contend with, making each guitar just a little bit unique.
What a shame that the best way to buy a musical instrument - in this day and age of never having to leave the house to actually shop - is still to pick it up, play it, listen to it, and feel it, right?