I have a sail cover made of Sunbrella type material for my Odyssey sail, which I use when the boat is moored somewhere safe for more than a day or two.  It keeps the sail clean and also presumably will prolong its life, though some folk with Odyssey sails, such as Annie Hill, never put a sail cover on.  The material is UV resistant, though all material will eventually degrade.  If your boat is going to sit on a mooring or marina for long periods it makes sense to have a cover.

Cheers Gary,

Found an old post saying that the name has changed from Odyssey 111 to Odyssey.  Do you use a sail cover or do you leave the sail open?  Also did you use v69 thread and venture tape when you made your sail?

All the best.

Having a look at the cloth used by most people and everyone seems to agree on 'Odyssey 111'.  I had a look on a website that I get trade price from and they only list;

Odyssey, Odyssey fr, Odyssey soft touch.  Are any of these an equivalent? 

Also not sure what weight fabric is best for a small boat, also looked at clipper cloth but it is 11oz is this too much for a 21 footer with a sa/disp-18.81?