Ink for Marking Transistors

[audiomaticmastering]

This seems like a simple question, but I've spent more time than I'd like to admit trying to figure this one out. What did they used to use to mark black transistors? I've tried sharpies and grease pencils and various water based paint markers, and nothing really seems to work. Been thinking about trying enamel paint like you would use on a plastic model, but I'm worried something that intense might damage the transistor. Does anyone on here have an idea of what the correct ink or paint is? Attaching a pic of what I'm talking about for reference. Thanks!

 

[OneRoomStudio]

I’ve used nail polish before, and that worked fine.

 

[CJ]

Get that stuff they use at pick n pull for marking greasy auto parts that stuff is amazing