What type of silkscreen ink is used in PCB manufacturing?
Try 'Epoxy Ink PCB Screen Printing' in your favorite search engine.

Here's one source, and the ink description gives away the desirable properties regarding substrate supported, adhesion qualities, curing process and immunity to acid/alkali treatment.

Du-Pont PCB silkscreen inks

Nazdar

Another co. I had never heard about

PS: No personal experience with those. For low volume usage, and DIY silk-screen, I believe people have used inks used for ceramic painting, which need to be cured at high temperature.