This versatile custom vest is cut from smooth merino wool. The finish has a slight luster to it, natural wrinkle resistance, and natural stretch which makes it a great choice. Natural stretch (sometimes described as mechanical stretch) is a woven technique that uses the natural bounce-back of refined wool combined with weaving tension and final finishing of the fabric to obtain the stretch characteristic without using elastic within the compositiThis versatile custom vest is cut from smooth merino wool. The finish has a slight luster to it, natural wrinkle resistance, and natural stretch which makes it a great choice. Natural stretch (sometimes described as mechanical stretch) is a woven technique that uses the natural bounce-back of refined wool combined with weaving tension and final finishing of the fabric to obtain the stretch characteristic without using elastic within the composition. The mid-tone shade of navy is a classic one that works well with all kinds of shirting.on. The mid-tone shade of navy is a classic one that works well with all kinds of shirting.