Sail design seems to me such a dark art that to try and find good written articles on how to design sails are few and far between, in particular most articles are written about slow speed dinghy sails which are not much use to A cats where the wind is almost constantly apparent wind. Does anybody know of any good websites / books etc that fill in a few gaps for me. My long term intention is start to build a few sails for no other reason than to try and understand them more.

I would start with talking to Tony Arrends. You can find him on the A-cat site. I think that he will talk to you, but he does make and sell sails. Jay and Pease are great resources, but again they are in the business.

It never hurts to ask the best about sail design ,its then up to those that make em, to part with the info your looking for.I really hope those questions are answered here in these forums.The more info we have the faster we can all go ;-)

Zhik