Hagoromo Fulltouch: The Legendary Chalk Hoarded by Mathematiciansk

Hagoromo chalk — Hagoromo Bungu, the Japanese office supply and chalk company, sold over 90 million pieces of chalk a year at its peak in 1990. HowStuffWorks

You have probably spent your life laboring under the misapprehension that all chalk is the same. Chalk — you know, the dusty white sticks you use to write on a chalkboard? Chalkboards — the thing they used in classrooms before the 1990s to visually demonstrate the subject matter being discussed in class? It's possible you missed that particular period of history.

Which might be why you've probably never heard of Hagoromo Fulltouch Chalk — unless, of course, you're a mathematician. Chalkboards have been disappearing from educational institutions for decades, but math is possibly its last stronghold. Mathematicians prefer writing complex theorems in chalk than with a whiteboard marker or a smartboard. And Hagoromo chalk has been described as the "Rolls-Royce of chalk."

Founded in 1932 in Nagoya, Japan, the company that became Hagoromo Bungu barely survived WWII, but went on to produce 90 million sticks of chalk a year by 1990. By this time, mathematicians from all over the world coveted the product. According to chalk connoisseurs, it's dense and difficult to break, produces very little dust, writes more smoothly and erases more cleanly than any other chalk in existence.

The Stockpiling Begins

After the company's sales peaked in 1990, though, chalkboards began disappearing around the globe, and with it sales of the world's most sought after chalk. In 2014, Takayasu Watanabe, the head of the third-generation family business and grandson of Hagoromo's founder, announced he was in very poor health and rather than saddle his three daughters with a flagging company, he would just shut down production.

There was, of course, an uproar amongst the world's mathematicians. Academics began stockpiling the stuff — calculating how much Hagoromo they needed to last them the remainder of their careers. Math professors filled home closets with the stuff and began selling it to each other in faculty lounges — these were suspenseful times in the math world.

But then, Shin Hyeong-seok rode in on his white horse and saved the day — at least for the time being. A Korean school teacher, Shin had been importing Hagoromo chalk to Korea for a decade, and approached Watanabe about buying the secret formula for Hagoromo chalk. After some serious deliberation, Watanabe gave in and gifted Shin the equipment to make the chalk, as well as the mysterious secret chalk recipe. Not only that, the identical twin brothers who had been primarily making Watanabe's chalk moved to South Korea to take over Shin's manufacturing of Hagoromo.

So the math world can heave a sigh of relief for now. Until, of course, the universities start taking their chalkboards away.