Top-notch clays are made in a labor-intensive process that requires beating all air out of the clay, hand-rolling each pipe before molding it, piercing with a fine wire, and careful firing. Traditionally, clay pipes are un-glazed. Clays burn “hot” in comparison to other types of pipes, so they can be difficult to smoke. However, unlike other materials, a well-made pipe
gives a “pure” smoke with no flavor addition from the pipe bowl. Clay pipes were once considered disposable items and the large quantities discarded in the past are useful aids for dating archaeological sites. The muddy bottom of the Thames has yielded up hundreds of thousands of them.