Ralph Greenleaf chalk, the stuff that says the odd word "chakt" on it, and Ralph's repro signature on it, is so rare that when my friend Ed Palmer turned it up he was afraid that other collectors would believe he whipped it up himself. It is square blue chalk, with a blue and white label. Well, I just purchased a box of 12 chalks and 8 of them were autographed by famous players. One of them was a piece of this Greenleaf. On the 4 sides, it says Ralph, Greenleaf, Ralph, Greenleaf. Under these words Greenleaf himself personally autographed each word, so it says Ralph Greenleaf twice on the cube and on one side he dated it 1948. Another piece is a National Tournament that has Greenleaf's autograph and that piece appears to have been autographed at the same time and with the same pen as the other 6 autographs. The other 6 are signed on pieces of Clik chalk from Brunswick. The Irving Crane piece is dated 1937 by Crane above his autograph. Others include Mosconi, Seaback, Diehl, Procita, and Rudolph. And the autographs compare perfectly with autographs known to be originals that I own. They also correspond to the 1937 championship players. Too bad he didn't get them all but that's ok. Pretty cool.