In rib lacing the rib cap-strips are wrapped in fabric tape and the covering fabric sewn to that tape. The stitches are much smaller and the reinforcing tape narrower.
There are several methods used to make the stitches one of which is known as "German two-needle" or "Focke-Wulf" stitching. After the fabric is shrunk a pencil line is drawn along the center of each underlying rib, then two lengths of thread are prepared each with its own curved needle. Alternating stitches are then made along the length of the pencil line first with one needle, then the other. This results in a neat, even stitch which can then be covered by a narrow (+/- 3cm) finishing tape.
(side view)
Another method used in Europe is the Swiss "Z' stitch in which a single needle is used to make a stitch across the rib starting from the same side and finishing with a knot on the opposide side each time. Between each stitch the thread remains on top of the fabric and crosses to the starting side, creating the distinctive "Z" appearance.
(Rib seen from above)
