What do you machine builders use to mark the machines (serial number or name)? I want to be able to write finely on my machines. Any recommendation as to what engraving pen/marker to get and where online? Thank you guys in advance. I am also doing some rebuilding on some of my coils and want to engrave stuff on it. simple stuff really... numbers, text. I am not going to be engraving artwork. any help would be appreciated ! thanks in advance.