I use the Blum clear plastic ones for most shelving needs. They have a steel pin for strength, but a smooth flat surface to keep from marring your shelf. On frame-less cabinetry you should use the ones that lock the shelf in (we are in CA. and refer to them as earthquake type), because in theory someone including kids can pull the entire shelf out on themselves. The frame on framed cabinetry keeps the shelves from coming forward but frame-less has no built in stops.
Chris...