"To maximize the yield from their brief grain-growing season and because that harvest often remains green, Scandinavians traditionally bake it into flatbreads for the most prudent winter storage and eating. When lightly floured, this long, hobnailed wood cylinder notches the rye or oat knackebrods known simply as Swedish hardtrack. This 10-inch pin quickly imprints standard-sized loaves with one pass; 3/8-inch-deep knobs score the dough to restrict its leavened rise. Hardtrack rolling pins, most often manufactured in maple, generally measure 17in in overall length." (The Well-Tooled Kitchen by Fred Bridge and Jean E. Tibbetts)