When we go on job sites, this is the chalk we use. No one else uses it, so it is easy to determine which chalk lines are ours. It also does not stain the concrete (like red chalk can), so it is safe for stained concrete flooring. It is also easy to pour, and costs no more than other colors.
Accessories:
This Old House (1-year) from The Time Inc. Magazine Company (Magazine) - Usually ships in 1 to 3 months