Stavanger, Sunday
Neville, I have made two sails from Odyssey III and found it to be a super-easy material to work with both when lofting and cutting it, and when sewing it. I believe it is strong enough for most jobs (6.5oz). In addition to the 11oz Top Gun, there is also the Topyssey at 8.5oz. It looks very much like the Odyssey, but is just a bit firmer.
I think that Odyssey III would be strong enough for most junk sails, in particular if one avoids making the top panels too big (better make them a bit smaller than the others). The webbing I use for roping is 2" polyester seatbelt webbing. This is strong and stiff enough.
The trick is to let the boltrope, battens and sheetlets be connected in such a way that the sailcloth is not involved. The sailcoth’s only job is to collect the wind. No strengthening patches or metal grommets are needed in any corner as webbing hoops spreads the loads so much better (here and here). Also using batten pockets helps in spreading the load. This method of relying on the boltrope is the original Chinese way as their sailcloth was/is so weak compared to what we use.
I bought both the Odyssey III, the 2" webbing and the T-90 sewing thread from Rochford, USA.
Good luck! Arne
PS: If the sail develops creases, it is not the Odyssey’s fault, but rather the fault of the sailmaker and rigger. If done right, the sail will set all right.