While not a research-level math question, I'm sure this is a question of interest to many research-level mathematicians, whose expertise I seek.

At RIMS (in Kyoto) in 2005, they had the best white chalk I've seen anywhere. It's slightly larger than standard American chalk, harder, heavier, and most importantly covered with some enamel-like coating that one must rub through (on the end) to be able to write with. One's hands don't rub through the coating, and thus don't get chalky.

Are there any U.S. manufacturers of such?

EDIT: even though someone has given a link whereby to order this stuff from Japan, I would still be delighted to hear about American products that beat Binney & Smith.

We here in New York have also long sought to secure supplies of this amazingly high quality chalk. It is called Hagoromo "Fulltouch" chalk, and my colleague Jonas Reitz wrote to the company, since the chalk does not seem to be available anywhere in the US, and got a letter in reply directly from the company president (with fairly OK English) concerning prices and rates to the US. It would come to 3 dollars per stick, and we considered that. 

Meanwhile, one of our postdocs with connections to Japan was able to arrange a small supply that way, and this is the message our administrative assistant sent out (provided with permission):


  
    To All GC Math Ph.D. Program Faculty, 
    
    I am happy to report that we have managed (thorough the good graces of our postdoc Yu Yasufuku) to get a limited supply of Hagoromo "Fulltouch" chalk which is made in Japan and is not available for sale in the United States.  We have been trying unsuccessfully to get this “miracle” chalk for years, but finally our prayers have been answered.  Users of this chalk report that it is the “Rolls Royce” of chalk; for you oenophiles, it may be thought of as the “Chateau Lafite Rothschild” of chalk, or, for you baseball fans, the “Babe Ruth” of chalk… well, you get the idea.  
    
    I have heard it said that it is impossible to make a mathematical mistake when writing with this chalk, but I am somewhat dubious of this claim.
    
    The chalk was “smuggled” in stick by stick carried in the beaks of birds (well, practically), so the supply is very limited.  We have, however, worked out a distribution system that seems the fairest and that should allow our stash to last for about 3 semesters. Faculty members teaching at GC will get ten sticks of chalk per semester, and those not teaching but who are coordinating (or co-coordinating) a math seminar at the GC and is a member of the Math Doctoral Faculty will each get 2 sticks per semester.  This will repeat each semester until the chalk is gone.  Faculty should save this chalk for use only during their most important lectures or when working on their most important theorems.  
    
    If you currently fall into one of the two categories listed above, please stop by to see me for your chalk and I will check you off of my list.  Hopefully, after spring 2011, another supply of these magical white sticks can be procured on the black or gray market, or perhaps Hagoromo will begin distribution in the U.S.
    
    At any rate, enjoy your chalk!  Use it wisely.  
    
    Best,
    
    Rob
    
    Robert S. Landsman, Assistant Program Officer, CUNY Ph.D. Program in Mathematics 
  

