Upon hearing of the Battle of Fort Carillon (Ticonderoga), students had the chance to "scrimshaw" their own "powder horns". Using bananas, which resemble the shape of a powder horn like those carried by explorers and soldiers in the 18th and 19th centuries, our students carved their own images and messages into their powder horns using a map pin. The images appear to darken almost immediately, leaving the effect of a fully-decorated and important piece of equipment that was a necessity for troops on the move.
Read more about my personal experience with Daniel Dwight's 1750s-era powder horn at Fort Ticonderoga.
please see our lesson set on the subject, including this idea from the fort itself.