Egan Cleon J: Woven papermaking drainage fabric having four shed weave pattern and weft threads of alternating diameter. Albany International, Quarles & Brady, December 3, 1974: US3851681 (29 worldwide citation)

A papermaking fabric woven from synthetic monofilaments is shown in which the warp threads pass under one and then over three weft threads in a repeated pattern, and the weft threads alternate in diameter to develop a fabric wear surface that is uneven with the average level of the smaller diameter ...