I recently replaced my jib with a triradial laminate.
I didn't want to mess up the sail's shape on the leech with Sunbrella, so I dutifully cover it each time I'm done sailing.
The sail cover is the length of the luff, has a halyard
attachment, zipper the length of the luff and a width in excess of the diameter of the sail at the clew when it's furled.
There is a zigzag line running from top to bottom which when pulled, nicely cinches up the cover.
When it's pulled tight, and then held by a cam cleat on the lower end of the cover, it won't flog in the wind
There's a pocket to hold the extra line.
It only takes a few minutes to install and remove.