What is the best way to permanently write on plastic where sharpie markers rub off way to easy?

Question

Specifically on a USB flash drive and MP3 player with a plastic casing.

Also I found "Itoya Nikko Permanent Pens" that claim to write on metal; does anyone know about these? link: http://www.dickblick.com/zz207/06/

Answer 1

Try an enamel paint pen. you can buy them at the craft store. they have to dry for a few minutes, but it's paint like nail polish. it won't rub off