Most PCBs have a component legend to show which component goes where and is known as Silkscreen or Legend. This is a printing process and the must be cured.
Eurocircuits PCB Manufacturing
Part 21 - Silk screen and cure
Easy Silk Screening with Recycled Materials - Oh, The Things We'll Make!
Legend Print - Eurocircuits Eurocircuits
Part 21 - Silk screen and cure
Silk-screen and Cure - Eurocircuits Silk-screen and Cure
MAKE COOL THINGS » screenprinting
Anyone aware of custom PCB houses that do full-color silkscreen? : r/AskElectronics
Silk screen on exposed PCB pads?
First Board made in KiCad -> Silkscreen Issues and a Circle - #6 by maui - Manufacturing - KiCad.info Forums