[fnordfnordfnord]

I didn't mean to say that it wasn't possible, you probably don't need a subjective measure of quality. I think you could empirically discover some objective characteristics of good chalk that would do the trick. You could at least quickly reject the worst chalk which is too brittle and too hard. I meant to say that there was and is no way that is recognized sufficiently universally that enables one to specify a chalk with the desirable properties to a gov't purchasing agent such that s/he can buy the right stuff.

[ars]

Specify bending strength, the chalk must not snap under specified force. Next define a writing pressure, angle and stroke speed and require fewer than x blank areas in the line. Require that the line width be within a specific tolerance, not too thick not too thin.

Maybe a spec like this doesn't exist now, but you could use the good chalk and write the spec based on how it did.

[fnordfnordfnord]

The trouble is that the places that sell chalk to universities don't rate chalk like this. Like I said in another post ITT, we derped around for a couple years before we just gave up and installed the damn whiteboards.