Ok Otis Here Goes
Place the telltails about 12 inches aft of the luff. You should end aft of the sacrificial. This the piece of cloth sewn to the luff of the sail, which protects it form the sun while furled. Measure the luff and divide it in thirds. Place your telltails at every third. Usually a red one on port and a green one on starboard. A telltail will go on each side of the sail one slightly above the other. Also placing them on a seam, as they will have a tendancy to hang up.Fair WindsCap'n Dave