Use to use Jim Dunlop .73 Nylon, using .60 now. Not too hard so that it catches on the strings (but hard enough for adequate power), and not too floppy like it was made from an ice cream tub. Great for pinch harmonics, speed picking, etc as the pick bends/slides off the strings easily. Even when worn, still easy to use. Fender picks suck - snapped two of them first go; brittle.