My signature block: 20 years ago, when I was first getting started in the arts, I went by the name ehmdott which is " MDOTT " or "M." spelled fancy. My signature spells MDOTT and then I boxed it in and flipped it sideways.
An artist's signature works much like a business logo or any other trademark that was created to copyright a product, service or just generally be recognizable. An artist's signature is a calling card. Signing a painting claims ownership, gives additional value, and marks it as a complete, sellable piece.