If you've ever visited a maritime or nautical museum, you've probably seen examples of scrimshaw, artwork that's made by engraving designs and pictures in a piece of whalebone.
Back in the day before sailors had iPods they often passed the time at sea by carving. Scrimshaw is the name for the articles they made, typically of whalebone, shells, or tusks, starting in the mid-1700's. The word's origins are still in the to do column of etymologists; all of the earliest citations are American. Someone who makes scrimshaw is called a scrimshander.