Key pattern

Key pattern is the generic term for an interlocking geometric motif made from straight lines or bars that intersect to form rectilinear spiral shapes.^[1][2][3] According to Allen and Anderson, the negative space between the lines or bars of a key pattern “resemb[es] the L- or T-shaped slots in an ordinary key to allow it to pass the wards of the lock.”^[4]

Key patterns have been discovered and used in ornamentation by a number of global cultures in human history, and are thought to largely have been designed independently of each other.^[4][5] The earliest examples of key patterns are seen in textile ornaments from Mezin, Ukraine, dated to approximately 23,000 B.C.^[5][6][7] Key patterns were also common in textile and ceramic ornamentation during the Neolithic period, with examples found among archeological discoveries in present-day Fiji, Peru, Mexico, Moldova, Romania, Hungary, Yugoslavia, and Greece,^[4][5][6][7] as well as in pre-Christian Celtic art.^[1][2][3] The oldest known pair of pants, wool trousers found in a grave dated to approximately 1038-926 B.C. in present-day western China, have a decorative band of key patterns woven into them.^[8] In addition, extant examples of early medieval Insular art, such as stone decorations and illuminated manuscripts, as well as Japanese, Chinese, and Islamic decorative arts from different periods, feature key patterns.^{[3][4][9][10]}

Celtic mazes, Greek frets, and xicalcoliuhquis are examples of well-known designs that are considered to be key patterns.^[2][4][11]