“J” for “Jazz”. The J1 Etched is a 10mil single-ply head featuring a unique textured surface specifically designed for brushwork and the jazz idioms. These 10mil single-ply heads have an etched finish that’s ideal for brushes, but doesn’t chip away under sticks. With a warm, organic tone and soft feel, the J1 emits a natural earthiness similar to calfskin – but without the problems.