Chalk of Champions

Mathematicians prefer Hagoromo Fulltouch chalk for its high quality and ease of use. But then the company went out of business in 2015, citing low sales due to new technology like whiteboards and computer screens. What to do? Mathematicians brought up all the Hagoromo Fulltouch chalk they could, and will try to make it last. Great Big Story reports on the fanatical fans of this premium chalk. (via Metafilter)