In writing this week about the baseball cap, I got stuck on a detail that didn’t make the final edit of that piece but did send me down an online rabbit hole featuring several dubious message boards, patents spanning several decades, and, briefly, a three-wheeled motorcycle*. All in search of the story of elusive — and delightfully named — tri-glide slide.
If you haven’t encountered this tuneful triplet of syllables before, the tri-glide slide is a flat, square, adjustable loop that regularly features on harnesses, diving masks, bra straps, and — the item that sparked my own interest — baseball caps. It also goes by webbing slide, tri-glide buckle, or plastic slide.
What is the origin of this unremarked but essential bit of gear? This type of cinching tech can arguably be traced at least as far back as the development of the stock (read: cowboy) saddle, which opted for variable adjustment around a horse’s barrel (read: stomach) rather than girths (read: belts) used on English saddles. But perhaps the most direct source of the webbing slide in clothing appears in Britain in the early 1900s.
Between the Boer War and the start of the Great War, there was a significant change in military gear. Traditional leather belts and harnesses slowly began to give way to a more functional material in the form of cotton webbing, an innovative bit of kit first developed for the British army by the recently founded Mills Equipment Company.
But with new material came new requirements. Unlike leather bands, which came fitted with buckles and punch holes, webbing allowed for variable and minute adjustments but required a mechanism that enabled smooth and secure fastening. As a simple but inspired solution, enter the grandparent of today’s tri-glide, which can be seen below.
In the decades since Mills Equipment’s innovation, webbing (albeit no longer necessarily in cotton) has become standard military issue across the globe and the lowly webbing slide — whether in metal or plastic, on a military belt or civilian cap — continues its ubiquitous and unsung service.
*If you’re wondering, the motorbike detour was courtesy of a model of Harley-Davidson called the Tri Glide Ultra, in case you happen to be in the market for a three-wheeled hog.