Aerial silks (also known as aerial contortion, aerial ribbons, aerial tissues, fabric, ribbon, or tissu) is a type of performance in which one or more artists perform aerial acrobatics while hanging from a specialist fabric. The fabric may be hung as two pieces, or a single piece, folded to make a loop, classified as hammock silks. Performers climb the suspended fabric without the use of safety lines and rely only on their training and skill to ensure safety. They use the fabric to wrap, suspend, drop, swing, and spiral their bodies into and out of various positions. The fabric may also be used to fly through the air, striking poses and figures. Some performers use rosin (dried or mixed with rubbing alcohol) on their hands and feet to increase the friction and grip on the fabric. Aerial silks is a demanding art and requires a high degree of strength, power, flexibility, courage, stamina, and grace to practice.