Guitar picks are available in a range of sizes, materials, gauges and styles, and all of these attributes correspond to different attack, tone and feel, which in turn suits different genres and styles of playing. Lighter gauge, or thickness, picks are good for strumming and produce a more delicate sound. Heavier gauge picks are more suited to single note picking, which is common for metal and rock and, surprising to some, jazz. Picks are made from multiple materials, but the most common are plastics, such as cellulose, nylon and delrin, metal or in some cases, bone or wood. These materials all produce different tones, depending on the type of string and style of the player. Picks are shaped in the common plectrum or rounded edge triangle shape, but for styles like country and folk that have a lot of finger picking, thumb picks and finger picks are common.