Masonite, also called Quartboard or pressboard,^[2] is a type of engineered wood made of steam-cooked and pressure-molded wood or paper fibers. The fibers form a stiff, dense material in a range of weights.^[3]

The process was formulated and patented by William H. Mason.^[4]

Masonite has been widely used in traditional school and office products such as spiral-bound notebooks and three-ring binders, but its unique physical characteristics lend itself readily to a variety of end-uses, including (but not limited to) document storage, filing supplies (classification and file folders), report covers, folding cartons, tags, labels, and industrial applications.^[5][6][7]

In 1898, a product resembling Masonite (hardboard) was first made in England by hot-pressing waste paper.^[8]

In 1924, Masonite was patented in Laurel, Mississippi,^[9] by William H. Mason, who was a friend and protégé of Thomas Edison.^[10]

In 1929, the company initiated mass production of its product.^{[citation needed]}

In the 1930s and 1940s, Masonite was used for applications including doors, roofing, walls, desktops, guitars (e.g., Danelectro), and canoes. It was sometimes used for house siding. Similar "tempered hardboard" is now a generic product made by many forest product companies.^{[citation needed]}

In 1972, the Masonite Corporation entered the door business as a supplier of facings.^[11]

In 2001, the Masonite Corporation was purchased by Premdor Corporation, a door maker, from its former parent International Paper. It no longer supplies generic hardboard.^{[citation needed]}

Masonite is formed using the Mason method,^[12] in which wood chips are disintegrated by saturating them with 100-pound-per-square-inch (690 kPa) steam, then increasing the steam or air pressure to 400 pounds per square inch (2,800 kPa) and suddenly releasing them through an orifice to atmospheric pressure. Forming the fibers into boards on a screen, the boards are then pressed and heated to form the finished product with a smooth burnished finish. (Later a dry process with two burnished surfaces was also used.) The original lignin in the wood serves to bond the fibers without any added adhesive. The long fibers give Masonite a high bending strength, tensile strength, density, and stability. Unlike other composite wood panels, no formaldehyde-based resins are used to bind the fibers in Masonite.^{[citation needed]}

Masonite may contain recycled fiber content (including post-consumer waste), and is typically itself recyclable and biodegradable, making it an environmentally-sound choice for those seeking an alternative to petroleum-derived substrates.

Masonite has also been made from cornstalks.^[13]

Artists have often used it as a support for painting,^[14][15] and in artistic media such as linocut printing. Masonite's smooth surface makes it a suitable material for table tennis tables and skateboard ramps.^{[citation needed]}

Masonite is used by moving companies. Among other things, they use it to protect the walls of buildings where they work, and lay on floors to enable smooth rolling of dollies loaded with goods.^[16]

Masonite swells and rots over time when exposed to the elements, and may prematurely deteriorate when it is used as exterior siding. In 1996, International Paper (IP) lost a class action suit brought by homeowners whose Masonite siding had deteriorated. The jury found that IP's Masonite siding was defective.^[17]

• Fiberboard – Engineered wood product made out of wood fibers
• Oriented strand board – Engineered wood particle board
• Paintings on masonite – Series of paintings by Joan MiróPages displaying short descriptions of redirect targets
• Particle board – Glued wood product
• Plywood – Manufactured wood panel made from thin sheets of wood veneer

• Media related to Masonite at Wikimedia Commons
• The dictionary definition of masonite at Wiktionary