Proline Decorative Concrete Systems 2BL 20" x 20" Blue Stone Touch Up Concrete Stamp without Handles. Blue Stone is a rugged pattern. Large deposits of natural Blue Stone are found near Derbyshire, England. The term blue stone is also used for the dolerite stones at Stonehenge. This brawny pattern offers an aggressive texture without the work or maintenance of grout lines. This mountainous and weathered texture makes a bold statement. Proline was the innovator of the seamless texture skins, made to overlap each other for a simple application. For easy installation, all Seamless Texture mats come with handles, with the exception of the touch up size.