The stitching and webbing at the head and tack of furling genoas and at clew of furling mainsails is exposed to sunlight all the time, which leads to deterioration. Unfortunately, this loss of strength is virtually invisible to the eye and usually only shows up when the stitching or webbing fails completely. This almost always occurs when a good breeze is blowing, which makes the failure dramatic and very inconvenient.
The first step in avoiding these problems is to have these parts of your sails checked and repaired on a regular basis by your sailmaker. Think of it as changing the oil in your car! In the early years of your sails, this will just mean re-stitching the webbing. However, after three or four years the webbing should be completely replaced.
Given the upcoming change of season, it's a perfect time to have your sails checked. If you have a roller furling genoa and/or a roller furling mainsail, assume the worst and have the stitching and webbing gone over and repaired. You'll be glad you did!
Also, you should know, that UK Sailmakers puts the UV cover over the webbing braids to protect them from the sun. See the top right picture and compare it to the sail with the green cover made by another sailmaker. Details like this may make a UK Sailmakers sail cost more upfront, but quality details like this show that all sails are not alike. Quality details make sails that last longer and allow you to sail stress free because no one wants to have a sail failure while out with family or friends.