My wife works as an Applications Engineer and used a Focused Ion Beam Scanning Electron Microscope (FIB-SEM) to mill a piece of silicone and draw the Magpul logo. I am a bit of a fan of Magpul. I even have a “Magpul” license plate.

In the photo you can see the View Field. The Magpul text is 40 microns wide which makes that less than the thickness of a human hair.

Here is a different angle.