Linoleum is a floor covering made 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.
Between the time of its invention in 1860 and its being superseded by other hard floor coverings in the 1950s, linoleum was considered to be an excellent, inexpensive material for high use areas. In the late nineteenth and early twentieth centuries, it was favored in hallways and passages, and as a surround for carpet squares. However, most people associate linoleum with its common twentieth century use on kitchen floors. Its water resistance enabled easy maintenance of sanitary conditions and its resilience made standing easier and reduced breakage of dropped china.
The best grades of linoleum were called "battleship linoleum", as a common use of this material was in warships. Actual battle experience showed this was an inappropriate material due to its flammability.
Linoleum as a floor covering has been largely replaced with polyvinyl chloride (yet still colloquially known as "linoleum"), which has similar properties of flexibility and durability, but which has greater brightness and translucency and which is relatively less flammable. The fire-retardant properties of PVC are due to chlorine-containing combustion products, some of which are highly toxic. Dioxins are released by burning PVC , and are toxic even in very small quantities. While the polymer itself is generally considered safe, additives such as plasticizers and unintentional impurities such as free monomers are considered a hazard by some: see the health and safety section of the main PVC article for more information and references.
Because it is made of organic materials and is purportedly non-allergenic in nature, high quality linoleum is still in use in many places (especially in non-allergenic homes, hospitals and health care facilities). The design and inlaying of various colors to form patterns reflecting the shape and use of a room is a highly respected craft.