Product Description Applications include interior layout, roofing, siding, and paneling. For interior or exterior use. ProChalk Standard for your basic chalk line needs that are easier to clean up or let wear away naturally. From the Manufacturer Ultra-Fine chalk is formulated to achieve a perfect line every time. Brilliant color tones provide strong, sharp lines. From the brightest pigments in the industry, we produce standard colors plus our unique, fluorescent Glo-Orange and Glo Lime for improved visibility.