April 29 is National Zipper Day, a day to celebrate the humble and extensively useful zipper. A thing that I suspect most of us take for granted. I do believe that this most fantastic of fasteners is one of my favorites. It far surpasses other types of fasteners when it comes to ease, finger friendliness, and versatility in function. We use zippers on so many things…clothing, shoes, purses, backpacks, duffle bags, suitcases, sleeping bags, and tents. Better than buttons and brooches, less complicated than buckles and hooks, superior to snaps and safety pins, and quieter than velcro, zippers are the most preferred type of fastener for people of all ages.…