Celluloid thumb picks come in bags of 5 and 50. Available in 2 gauges Shell-colored Premium quality celluloid provides natural feel and warm, fat tone Available in multiple gauges Celluloid is one of the most popular guitar pick materials today. It's available in a wide variety of shapes, colors and thicknesses, and provides 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.