Thanks for all the great input, especially from you Rolf, I will try to post questions regularly as I progress. First of all I'll have to get my knowledge in order. I'm currently reading Frank Bethwaite's "High performance Sailing" and lot of things that happened to me in the past start making sense now. I will get "Art and science of sails". Any thoughts about CA Marchaj's "Sail performance" and perhaps "Aero-Hydro dynamics of sailing"? Perhaps somebody knows good books about craft of sailmaking. I see it this way, whether I'm going to make my own sails or not, a sailor can never know too much about sails.