Hi Matt,
I learned to make sails when I worked part time for a sailmaker in the early 80s. We were still hand designing and laying out sails, mostly crosscut, when I started. I was fortunate to work during the transition from dacron to mylar and from all hand layout to the methods already described in this string. Hand layout is an art and is easy after you have learned how and could easily and inexpensively be done at home. You could read some older books and experiment or find an old sailmaker and learn from him.
More likely it sounds like it will be easier for you to use computer software and get your designs cut for you. If you have that level of interest I suggest you try to get a part time job with a sailmaker to learn the business. If you stay interested, you may be able to be really useful to the sailmaker by sharing your software or improving their's. Many smaller sailmakers just buy generic sailmaking software and never learn how to "tweak" it to make it proprietary and differentiate their product. But the big advantage to any software is that when a design is good you can count on getting the same result time after time, unlike hand designed sails.
Most mylar sails can be glued together now using purpose built glue guns for a very robust seam without stitching and also very efficiently using benches that are about lower chest level. You can get the same result for lighter weight sails using double sided sticky tape (seam tape) which used to be used only to hold seams together until they were sewn. I have used that method very successfully on jibs, screachers, and very light mylar spinnakers. It would be good for A class main sails and maybe even heavier ones but I have not done that personally. For those lighter weight sails, I prefer using webbing for corners rather than metal grommets, both for weight savings and for ease of application. Just run a strip or two of webbing up one side of the corner and back down the other side leaving a loop on the corner to attach sheets or shackles to. Do that even if you have your sails built for you. Again, the exception might be for big mainsails that get really heavily loaded.
One last "trick" that you might find very useful, especially in your experimental phase. Cut sail designs out of paper and tape them together with the double sided sticky tape. Then set the paper sails on your boat and look at them (eyeball, camera, video, etc.) before committing yourself to some expensive mylar. You can make many sets of paper sails for the cost of one real sail and learn alot. Yes, they perform badly in strong wind, rain, etc. as you would expect so you do not try them in those conditions. They are just to see what a design would look like for real until you start to feel confident about what you see when you "fly" your sail designs on the computer.
On any design you are examining, it helps a lot to put draft stripe tape from luff to leach to accentuate the shape and make measurements easier directly or from photographs. Works great for sail trim during racing, too, of course. For "quick and dirty" measurements, you can use electrical tape but that will not stay on very well.
I hope these tips are useful. Have fun. At the very least, you are bound to learn more about sail shape and improve your sail trimming. I think you are going to be surprised to see what a huge difference even a 1/16 of an inch can make here and there!
Mike
