In removing a white Sunbrella UV cover off a furling jib we noticed something that didn’t seem very important at first glance. The sail had black ‘draft stripes,’ but the black color had faded underneath the Sunbrella cover.

That’s strange. The Sunbrella is supposed to protect the sail underneath, and if the Sunbrella is doing its job, what caused the black draft stripes to fade? The stripes look exactly like they have been in direct sunlight.

Well, it turns out that all Sunbrella colors don’t act the same, and it turns out that in our experience, the white color is the least durable of all the colors. In this case ‘durable’ means the ability to keep UV light from passing through the cover material.
The problem here is not really with the faded draft stripes. The problem is the sail itself has been cooked by the UV, and is substantially weaker than it would have been if some other color was chosen.

This particular sail was built in March of 1997. The owners rigorously remove the sail every November and store it below through the stormy winter months. It is re-installed around March or April. So it was 12 ½ years old when we took the cover off, but in another sense it was more like 6 years old.

The purpose here is certainly not to bash Sunbrella. It is the most durable material we know of for protecting sails from sunlight. But be careful in choosing white. Different colors, in particular the blues, seem to last 15 or 20 years! Other things have changed in the interim: in late 2008, the Sunbrella Warranty was extended from 5 years to 10 years. That may indicate an improvement in the product. If you are into warranties, keep in mind that the Sunbrella warranty covers the Sunbrella fabric only, not the sail it was supposed to protect. Google ‘sunbrella warrantee’ if you are interested.