When all layers of skin are required to seal a wound or cover tiny regions, a full-thickness skin graft is utilized. It is utilized when matching the color of the skin transplant to the native skin is critical. It may also be used when skin graft contractures (tightening and shortening) must be avoided. Finally, full-thickness skin grafts can be used to treat large areas of skin loss. The three main types of skin grafts are partial thickness, full thickness, and split thickness. Partial thickness skin grafts only reach the dermis layer of skin tissue; they do not go through the subcutaneous fat layer. Full thickness skin grafts include both epidermal and dermal layers; they are given to close wounds that penetrate into the muscle or bone. Split thickness skin grafts are made up of two separate pieces of skin: a thinner outer piece called a papilla and an inner piece called a dartos. This type of graft is used to cover small areas of skin damage. Full thickness skin grafts require surgery to remove the damaged skin and then replace it with healthy skin from another part of the body. The new skin will eventually grow back together at the site of the injury, forming a smooth surface with no scarring. This type of graft is needed to close wounds that penetrate into the muscle or bone.