Another case is the outline of the triangle rack behind the foot spot where the balls are racked in straight pool, since the outline of this area is strategically important throughout the game. Other markings may be a line drawn across the head string (or across the balk line with the "D", in British-style pool). Spots are often used to mark the head and foot spots on the cloth.
Books, even entire series of books, have been written on geometric and algebraic systems of aiming using the diamonds. These sights divide the playing surface into equal squares. There are seven along each long rail (with the side pocket interfering with where the seventh one would go, on pocket billiard tables) and three along each short rail, with each of the four corners counting as another in the mathematical systems that the diamonds are used to calculate. Sights, also known as diamonds (for their traditional shape), are inlaid at precise, evenly spaced positions along the rails of some tables (not usually on snooker tables) to aid in the aiming of bank or kick shots. Snooker cloth traditionally has a directional nap, upon which the balls behave differently when rolling against vs. This "speed" of the cloth affects the amounts of swerve and deflection of the balls, among other aspects of game finesse. By contrast, high-quality pool cloth is usually made of a napless weave such as worsted wool, which gives a much faster roll to the balls. This type of cloth is called a woollen cloth. Most bar tables, which get much use, use the slower, thicker blended felt because it is cheaper. Both the rails and slate beds are covered with 21–24-ounce billiard cloth (although some less expensive 19-ounce cloths are available) which is most often green in colour (representing the grass of the original lawn games that billiards evolved from), and consists of either a woven wool or wool- nylon blend called baize. for children's recreation rooms) still include wood, especially medium-density fibreboard and plywood, as well as plastics and other synthetic materials under various trade names.īilliard cloth (sometimes erroneously called felt) is a specific type of cloth that covers the top of the table's "playing area". Today, inexpensive but not very rigid or durable materials used for the beds of low-end tables (e.g. The early table beds were made of cloth-covered wooden boards. Tables for the home market usually use slate beds as well, but the slate is often thinner, down to about + 1⁄ 2 inch (13 mm).
When several pieces of slate are joined poorly it is possible for the resin to deform and cause an uneven playing surface it can also be difficult to move once joined. The gap between slates is filled with a hard-drying putty, epoxy or resin, then sanded to produce a seamless surface, before being covered with the cloth. Small pool tables may use only one or two pieces of slate, while carom, English billiards and tournament-size pool tables use three.
The bed table – the cloth-covered, horizontal playing surface – is, on high-quality equipment, made of solid, smooth slabs of slate, most often from Italy, Brazil or China. Snooker tables use an L-shaped profile, such as the L77 profile. K-55 cushions have cloth, usually canvas, vulcanized into the top of the rubber to adjust rebound accuracy and speed. On a carom table, the K-55 profile is used (with a somewhat sharper angle than pool cushions). When installed properly the distance from the nose of the cushion to the covered slate surface is 1 + 7⁄ 16 inches (37 mm) while using a regulation 2 + 1⁄ 4-inch (57 mm) ball set. The standard on American pool tables is the K-66 profile, which as defined by the Billiard Congress of America (BCA) has a base of 1 + 3⁄ 16 inches (30 mm) and a nose height of 1 inch (25 mm). The profile of the rail cushion, which is the cushion's angle in relation to the bed of the table, varies between table types. The purpose of the cushion rubber is to cause the billiard balls to rebound off the rubber while minimizing the loss of kinetic energy. The cushions are made from an elastic material such as vulcanized rubber (gum or synthetic). There are several different materials and design philosophies associated with cushion rubber. Parts and equipment Cushions Ĭushions (also sometimes called "rail cushions", "cushion rubber", or rarely "bumpers") are located on the inner sides of a table's wooden rails.