THE COSMETIC REPUBLIC Hairdressing Products. KERATIN FIBERS hair fibers #medium brown. The fastest and most effective way to end alopecia in an instant. It is made up of natural microfibers of vegetable keratin, made from the same protein as our hair. They are microfibres resistant to wind, rain and perspiration. Combine with MIST Fiber-Fixed Spray for a perfect, long-lasting finish. Available in 10 different shades.