When I lightly rub my finger over the signature(s) of a signed guitar I can literally feel the ink almost as if it was painted on instead of signed w/ a Sharpie. Is this necessarily a good sign of a fake or is it just likely that it was signed w/ a type of pen that had a heavy ink flow? (It's not like the ink is super thick, 3D or anything just slightly raised and detectable where the ink is heavier.)