A signature mistake

You hardcore baseball collectors know this already. I only learned it recently:

Don't offer a player a Sharpie for an autograph on a baseball. A Sharpie signature will bleed into the baseball. The weapon of choice is a blue ballpoint pen. Not black ballpoint, because that could be mistaken for a printed-on signature. So if you bring a Sharpie to the baseball stadium, I have to say: Ya Goof!