composition board, wood product produced in the form of a board or sheet, formed of cellulose fibers or particles derived from wood or other sources, and used principally as a building material. The oldest type of composition board is a relatively dense material known as hardboard, discovered accidentally in 1924 by the American scientist William Mason. After obtaining wood fibers by using high-pressure steam, Mason attempted to dry a matlike mass of them in a steam press. Because of a faulty valve, the press remained hot longer than had been planned and thus the first piece of hardboard was formed. In other forms of composition board the fibers are not as closely packed, and the density is correspondingly lower. Some of these boards find application as insulating and soundproofing materials. Other similar types are treated with waterproofing material, e.g., asphalt applied under pressure, and are usable as the sheathing of buildings. Such materials typically have a resistance to shearing forces exceeding that of plywood. Particle board, another form of composition board, is made by binding wood particles ranging in size from flakes to sawdust together with a suitable adhesive, such as a plastic resin, and pressing or extruding them to form sheets. Particle board is used as a cheaper substitute for plywood in some applications; but even though it has a higher density, it is less resistant to puncture and the effects of weather. When properly veneered it is suitable for making furniture. In its raw form it makes an excellent subflooring for dry locations.

composition, in art, the organization of forms and colors within the work of art. In traditional sculpture this means the arrangement of masses and planes. In representational painting it means the grouping of forms on a two-dimensional plane in depth. In abstract painting forms are generally composed on planes parallel to the picture surface. In illusionistic works (see illusionism) with advanced perspective, forms are arranged to accord with the laws of depth perception.

composition, in ancient and medieval law, a sum of money paid by a guilty party as satisfaction to the family of the person who was injured or killed. Failure to make the payment might justify retaliation in kind against the offender or his family. In earliest times, the payment was made as a result of a mutual agreement between the parties, but later it was imposed by law. In many societies the amount paid varied according to the rank of the person injured or slain. Composition reflected a transition from a system of feuds or blood revenge (see vendetta) to one where socially dangerous acts are primarily a concern of the state rather than of private persons and their families alone. The exaction of the payment recognized the outrage to the person and the family as the prime offense, but it tended to discourage disorder by providing a substitute for retributive killing or other violence. When, in addition to composition, a fine had to be paid to the state, the dangerous act approached the modern conception of a crime (see criminal law). This institution was known in all Germanic cultures, including Anglo-Saxon England, and was widespread in many parts of the world. It is still practiced in certain Middle Eastern countries. An example of composition is wergild [Old Eng.,=man's price], the payment made by a murderer to the family of a murdered person. Wergild was often paid to the king for loss of a subject and to the lord of the manor for the loss of a vassal as well as to the family of the deceased. The term composition is also used to refer to an agreement between an insolvent debtor and his creditor, whereby the creditor for some consideration, such as an immediate payment of a portion of the debt, waives the remainder and considers his claim satisfied.