I use this in my office (well, the Korean replication that's still sold). I firmly believe that good chalk on an enameled steel chalkboard is far superior to a whiteboard: it always erases cleanly, the ink never runs out, it writes with high contrast, and it's immensely satisfying to write with. The only downside is chalk dust.
By contrast, the cheap chalk the department buys for us is terrible. It squeaks, it snaps, it refuses to erase cleanly. And our conference room whiteboard markers are always dried up and don't write clearly.
I have yet to turn into an illicit chalk dealer, though.
This feels like part 1 of a 3 part series.
In Part 2, we must visit Japan to learn about how it came to be and why it went out of business.
And in Part 3, we go to S.Korea. We learn about the company thats producing chalk from the purchased recipe.
The successor, Umajirushi DC Chalk, is available here from JetPens (San Jose, USA), $1.80 for 6 sticks, or 30¢ per stick (also available in a 72 pack like shown in the video)
One day someone woke up and said "wow, those k cups are an environmental disaster"... I wonder if a similar thing will happen with dry erase markers. As a professor, I go through far more dry erase markers than chalk... When I am done with chalk there is just dust. Not sure if those dry things recycle, but no one I know puts them in the recycle bin.
Also, there are very, very good chalks at jetpens from Japan still being made.
So, I guess mathematicians hoarding original Hagoromo chalk now have to stop before they write down a theorem on the blackboard and ask themselves: is it chalk-worthy? [0]
When I graduated I bought my PhD advisor two boxes. It's great stuff. But beyond how dense and smooth it is, particularly good is the colored chalk. Most colored chalk doesn't erase well. Hagoromo erases completely, easily.
By contrast, the cheap chalk the department buys for us is terrible. It squeaks, it snaps, it refuses to erase cleanly. And our conference room whiteboard markers are always dried up and don't write clearly.
I have yet to turn into an illicit chalk dealer, though.