Relaxed skin tension lines (RSTL) are natural skin lines that indicate the direction of the collagen fibers in the skin of humans when the skin is relaxed. Albert F. Borges first described the concept of using RSTL for planning excisions of skin lesions on the face in 1984; as a result, they are sometimes referred to as Borges lines. RSTL become visible when the skin is relaxed and are traced by pinching at a right angle to the RSTL. Since scars become smaller and heal faster when the skin is under the least amount of tension, knowledge of the patient's RSTL can help surgeons know how to make a cut in the skin that optimizes cosmetic outcomes and reduces the time to heal.