You'll usually find ink inside a pen, automatically flowing through its tip, although years ago people had to dip a quill into a pot of ink to write with ink. Other ways ink is used include printing images, stamping information, and drawing pictures. Another ink is the fluid released by certain mollusks, like squids, to hide them from predators. Ink, from the Old French encre, "dark writing fluid," has the Greek root enkaiein, "to burn in."