Product Description One of the first polymers ever created, cellulose nitrate is made by reacting cotton fibers with nitric acid. Cellulloid was substituted for natural toroise shell picks in the early 1900s and is still one of the most popular pick materials available today. They are available in a wide variety of thicknesses, shapes, and colors, and provide a natural feel and warm, fat tone. From the Manufacturer The Planet Waves 1CBK4-100 is a 100-pack of premium celluloid picks in black, medium gauge.Celluloid is one of the most popular guitar pick materials today. Available in a wide variety of shapes, colors and thicknesses, celluloid is known for providing a natural feel and warm, fat tone. A man-made material, celluloid was first introduced in the early 1900's as a substitute for natural tortoise shell picks.Planet Waves, part of the D'Addario family of brands, is known for innovative, problem-solving, quality musical accessories. Planet Waves offers a complete line of award-winning accessories including cables, picks, tuners, capos, straps, humidifiers, maintenance tools and more.