Chalk will usually come in small blocks, plain paper wrapper. Also have the powdered form. A lot of sporting stores that feature BB'ing supply's will have it. Most heavy lifting gym's have a chalk box of powdered chalk. Lifters will just place the palm of their hands into the box and get it that way, dust flying everywhere. Power and Olympic lifter's can be covered with that white powder during a heavy workout. Really, from head to foot. Can usually tell a serious gym by the chalk in the air and on the lifter's.
If your hands are sweating during a workout be sure to dry them before applying block or powdered chalk. Can use chalk while using lifting straps also. For the most part, BB'er do not need chalk that much. Anyway, most commercial gym's frown on it or not allow it at all. Lifters will usually have a supply in their gym bag.
Rosin is another sticking element some lifter's will use. Problem is is that some times it can peel the skin off the palms when going for max lifts.....too sticky (this can happen with chalk also). As far as blackboard chalk goes, I have not a clue if it's the same grade. Just a guess...yes. Good Luck.
