Furling systems have been around a long time now, and work so well we kond of take them for granted. From the early days the genoa was a perfect sail to be rolled away - it had a long enough foot that the sail remained balanced even when deeply furled, and the sheet lead, whilst not ideal, did not need moving too much.
The sail remained balanced even when deeply furled
The problems that became clear were that the sail became fuller and fuller as the sail was reefed, and the boats ability to go to winddward was compromised.
We came up with the foam insert, running all the way up the luff
Elvstrøm Sails realized that this needed to be dealt with, and came up with the foam insert, running all the way up the luff. This created a differential diameter in the headfoil, which in turn furled the middle of the sail away faster than the corners. This proved enormously successful, and much copied. We are still using today.
UV protection has been used since those early days, and again has not changed much at all. The UV protection fabric used are much better now than then, and range from specially treated dacron to heavier Acrylics.
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