Toppik Hair Building Fibers Black is made of natural, colored keratin fibers- the same protein that makes up human hair which blend undetectably with existing hair strands to instantly create the appearance of naturally thick, full hair. They resist wind, rain and perspiration for long-lasting results in all conditions. They can be mixed to match virtually any hair color, hair fibers work for all hair types and textures. Also great for part lines, covering extension tracks and touching up roots between hair color appointments. Easily washes out with shampoo.