Curly maple is a term for maple wood that has a wavy or curly grain pattern that creates a three-dimensional effect. It is not a specific species of wood, but a variation of maple heartwood that is influenced by irregular growth of fiber cells. It is highly valued by furniture makers and musical instrument makers, especially for guitars and violins. The grain pattern is most noticeable when the wood is quartersawn, and the quality of the wood is determined by factors such as color, frequency, and intensity of the curls. Curly maple is also known by other names, such as flame, striped, tiger, sugar, rock, and quilted maple.