The Collaborative International Dictionary
Bristol \Bris"tol\, n. A seaport city in the west of England.
Bristol board, a kind of fine pasteboard, made with a smooth but usually unglazed surface.
Bristol brick, a brick of siliceous matter used for polishing cultery; -- originally manufactured at Bristol.
Bristol stone, rock crystal, or brilliant crystals of quartz, found in the mountain limestone near Bristol, and used in making ornaments, vases, etc. When polished, it is called Bristol diamond.
Wikipedia
Bristol board (also referred to as Bristol paper or Super white paper) is an uncoated, machine-finished paperboard. It is named after the city of Bristol in the southwest of England. Common sizes include 22.5″ × 28.5″ (572 × 724 mm) and its bulk thickness is .006 inches (0.15 mm) or higher and A4, A3, A2 and A1 Bristol board may be rated by the number of plies it contains or, in Europe, by its grammage of 220 to 250. It is normally white, but is also made in different colours.
Usage examples of "bristol board".
Then, since she had bought the art supplies, she acquired watercolor paper and Bristol board as well.
She pushed the seat back, put her feet up on the dash, and began sketching pearl-inlay designs on a piece of Bristol board.
Returning to her easel for the first time in months, she tried painting in oils, found her sense of color wanting, switched to pen-and-ink and filled pages of bristol board with tight, hyperrealistic faces.