In a warp knitted structure, all ends supplied from the same warp sheet normally have identical lapping because each is lapped by a guide attached to movements the same guide bar (Fig. 23.1). Beams (Fig.23.2) supply the warp sheets in parallel form to the guide bars, whose pattern control determines the timing and configu- ration of the lapping movements in the form of overlaps and underlaps. The needles intermesh the new overlaps through the old overlaps to form the intermeshed loop structure, Swin 8 Shog overlap Swing underlap Fig. 23.1 Guide bar lapping movement.