Can you just use a Dymo label maker? The tape is actually 1/2" tall and prints black lettering on white with a sticky back. I use it to label wires like the ethernet cables in my house. The lettering size is adjustable to 5 different sizes.
I’m aiming for a look cleaner / more professional than a labeler will give me. I have one but even the black-on-clear looks chintzy. It’s my fault: I tend to get perfectionist on stuff like this.