All our zippers are American-made by YKK in the USA. Even the pulls, which is a whole other issue. There is a huge variety of zippers, many ways to configure them, different materials from which they are manufactured and even different ways they can be operated. Our zippers have always been supplied by Supreme Zipper of Pennsylvania.
YKK is actually a Japanese-owned company that does a lot of manufacture in the USA. They keep us on our toes, tho, because they sometimes shift the place of manufacture of some of the zips we use. Manufacture has been moved to Japan, or to America, depending on the exact zipper. Supreme knows our requirements, and keeps us up to date.
We use Double Zippers on the center front of all our garments except the few, such as the ShirtJac, that have only buttons. A double zip can be opened at both bottom and top, or either one, or neither. Any outdoor garment that uses a single zipper is just not a serious garment. We generally use Vislon zippers because they are more tolerant of grit and cold than metal zippers. Also, Vislon is safer because it does not conduct electricity. We have been unable to find zippers whose performance is guaranteed in temperatures below -20F/-29C, so some of our garments, such as the All-Around Jac and the SkiJac, have storm flaps partly to insulate the zippers. The storm flaps also keep the zips from getting caked with ice and snow or clogged with grit.
We use the best American-made zippers we can find. We've heard more than once that Riri makes the best zips, but they are made in Italy, so we can't use them (even though all my grandparents were born in Italy).
Remarkably few problems with our zips have been brought t our attention. But, zippers do break down over time. There is plenty of info on the web about how to repair zips. Here is a a great short YouTube tutorial on fixing a zipper slider that is not zipping the teeth together. THANKS to Sterling Wong! Also, it turns out (should not have been a surprise) you can easily find online ZIPPER PLIERS designed for exactly this chore. Sterling's video shows how to do it with a standard needlenose pliers. And THANKS to UCAN Zippers USA for another similar video. There are lots more such videos out there
16 April 2022 --- Ralph