The art of pictures engraved on
ivory. There are various forms, such as ivory jewlery,
billiard balls, and
piano keys. Ivory as you know can be from
whale's teeth,
rhinocerous horn or
elephant tusk.
There is also microscrimshaw where things are engraved with painstaking detail, like the entire piece is the size of quarter. With this kind of detail you need a magnifying glass to see it all.
There are different ways of engraving, one way I've seen is to polish the ivory smooth, then use a fine pointed instrument, like a sewing needle, to put thousands of tiny dots in the material. This is known as stippling.
Then the artist rubs the color onto it, this can be ink, oil paint, or lampblack. Once the piece was covered with paint, the artist wipes it clean. The oil paint fills up the stipple marks but comes off the polished part.
Scrimshaw is painstaking work, but microscrimshaw is harder, requiring magnification to work. Some of it becomes jewlery, some an emblem or seal, others knife handles and gun grips.
The person doing the scrimshawing is the Scrimshander.