Every time I snap a chalk line, a huge cloud of chalk forms in the air. Why?
Most likely, you are also getting a dull, hard to see line. That’s most likely because the brand of chalk has a lower ratio of color to filler. In order for marking chalk to make a sharp, distinguishable line, there must be a much higher concentration of color. Then, when a chalk line is snapped, more color gets absorbed by the surface, and a truer line can be seen.