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. Assortment pack includes 8 Light (.50mm White Pearl), 9 Medium (.70mm Red Pearl), and 8 Heavy (1.0mm Black Pearl) picks.