Jim, I have been buying spray chalk from Rainbow Racing Systems , Spokane Washington. (800) 962-1011 or (509) 326-5470. A case of fuorescent orange was 48.00 for 12 cans. . They also have a UV sensitive chalk that disappears after about 10 days. that is 45.00 for 12 cans. The last catalog had white ,yellow, gren and blue and paint as well. I have an extra catalog -email your addrss and I'll drop; it in themail to you. Mike if anyone has any source that is cheaper please let me know ok?