The zipper, that ingenious mechanism: I’ve stared at it many times—sometimes in fury, sometimes frustration, sometimes even in sadness. The zipper: a kind of touchstone for my life, recalcitrant and stubborn when my children refused to go to school and used the zipper as their excuse; exasperating, even dangerous when down parkas blew open on subzero days; and now, hanging motionless in my closet, claiming the end for otherwise useful articles of clothing I have loved to wear. But even with their long history in obstructing my life, I still can’t figure out how zippers work, how roughly 800 teeth, 400 to a side, clasp together when a metal tongue passes over them one way, or how they unclasp when the metal tongue passes over them the other way. 

So, on to Wikipedia, in my own words: Basically, the two sides of a zipper are like perfectly fitted jigsaw pieces that come together with a tiny snap—what you hear, snap after snap, if you pull the zipper very slowly. But the average zip takes only a fraction of that time, somewhere around 400 snaps in a second.  That’s a lot of puzzle pieces coming together almost instantaneously.   

The zipper mechanism is ingenious: The puzzle pieces are fed into the slider with its convenient tab for the thumb and forefingers, the metal tongue I was talking about. The slider is Y shaped on the inside with the puzzle pieces sliding down either side of the Y and snapping together down at the bottom of the Y. They unsnap and slide open when the slider goes in the opposite direction. That’s what makes that pleasing zip sound for which zippers are named.

The earliest zipper design had parts named after the body’s more angular and violent fittings, “joints,” and “jaws.” These terms were soon replaced by the more elegant “ribs” and “grooves,” which suggest something more graceful, even breathless, perhaps aptly named given that the zipper’s first inventor, Whitcomb Judson, also invented the pneumatic railroad and must have thought a lot about what can easily and smoothly move along—or within or above—tracks.

The zipper was first used in the 1920s in things you needed to join quickly—boots and leather jackets and tobacco pouches, all of which sound to me like upper-class attire. But by the 1930s zippers were primarily promoted for children’s clothing because kids had to learn how to dress themselves as soon as they could and so, in this easy way, become self-reliant. 

I suspect the real reason zippers became popular was because everyone hated buttons, especially on boots on very wet days or the tiny ones numbering in the millions that ran up the fronts and backs of dresses. Of course, in the movies and maybe in real life, zippers running down the back of a dress might have helped seductions along, but that is all such zippers are good for. Just try zipping the back of a dress sometime without help and without extraordinarily long arms and an athletic torso; this may be why most dresses these days have minimal fastenings. 

The zipper is one of those lowly, but mighty, things. It can hold the memories of a lifetime between its tiny teeth. If it breaks, an article of clothing, usually a necessary article of clothing, like a winter coat or a fleece sweater, can no longer be opened or closed. All it takes is one of those tiny teeth going crooked, one among the hundreds of teeth, and from then on, the coat or sweater will hang useless in your closet. Year after year, you’ll see it and think, oh, it’s only the zipper that’s broken. Someday, I’ll take it in and get it repaired.