A reliable prosthetic or orthotic skin interface liner includes surfaces having a roughness or reduced coefficient of friction. The liner is for use as a skin interface between a limb and a prosthetic or orthotic device. The liner includes an elastomeric material defining a tubular member having exterior and interior surfaces, and a matting agent added to the elastomeric material to reduce the coefficient of friction of at least one of the exterior and interior surfaces of the tubular member. After releasing the liner from a mold or press, exposing the liner to a gas, e.g. air, causes the surfaces of the liner to turn matte or slightly roughened. As such, the liner may be more easily applied to the patient's affected area.