Toppik Hair Building Fibers, made of colored keratin protein, blend undetectably with existing hair strands to instantly create the appearance of naturally thick, full hair. Toppik Hair Fibers resist wind, rain, and perspiration for long-lasting results in all conditions. 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.