Linoleum is a floor covering mae from solidified linseed oil (linoxyn) in combination with wood flour or cork dust over a burlap or canvas backing. Pigments may be added to the materials used. The finest linoleum floors, known as 'inlaid', are extremely durable; they are made by joining and inlaying solid pieces of linoleum. Cheaper patterned linoleums came in different grades or gauges, and were printed with thinner layers which were more prone to wear and tear. Good quality linoleum is sufficiently flexible to be used in buildings in which more rigid material (such as ceramic tile) would crack.