Jim is right. Folding your Dacron sails for winter storage is fine. Additionally, modern laminates, like Contender ACL and Bainbridge Diax can also be folded for winter storage. If a sail is being stored for longer than one season, we recommend refolding the sail along different fold
lines periodically or rolling it if you have the space. The most important consideration for any sail storage is to make sure the sail is completely dry when you bag it and stored in a low humidity storage environment.
Bill