Then your back to zips again, which could work if keprt away from area of load ie the head and clew. You would start off with a sail the shape of a naish Boxer zip off 0.7 of a meter to have a normal outline and then another bit to leave you with a pinhead shaped sail. the characteristics of the sail would change greatly though. To keep the characteristics you would need to shorten the luff. Do do that in sections is going to need lots of buckles webbing etc.



the end result would be the 3 in 1 sail would probably cost the same as 2 sails and each size would not have the performance to match a solo sail.



I unfortunately had to make raceing dinghy sails. The customers were never happy. if it was light wind they wanted full sails, strong winds, flat sails and they could only register one suit per event. In the end we made them some sails with velcro seams and showed then haw to alter the shape to suit the comditions. All that for a boat the shape of a bath tub that might do 5kts in a Hurricane.



I have just remembered seeing a long time ago where intead of zipping off the leech/head area you zipped off the foot and used another clew eye 30 cm further up, a bit more like reefing a yacht sail. the sail had 2 sections you could zip off. But that was in the days before foot battens



All food for thought, better get back to making my 6.7



http://www.sailrepair.co.uk