ties, nettles, gaskets.. whatever
Dale, I'm not sure what Don will recommend, but in my opinion, you don't need 'em unless you are staying reefed for a while and want the sail's unused slab dressed up. I doesn't affect the shape. If the reef line is set up correctly to pull the clew backwards, the sail should be flat, anyway. I took the rope nettles out long ago and as a substitute, purchased some blue, 1 inch, flat dacron webbing cut to appropriate lengths. The ends are cut at 45 deg so they can be easily threaded through the intermediate cringles. I keep them stowed in a handy place. I use colored ties so they will be visible against the white sail as a reminder to remove them before releasing the reef lines. I've seen other sailors use thin colored cord, 1/8 or 5/64 in, but I like the webbing.I always keep a few ties close at hand, never know when you might need to tie something off in a hurry.