Our 420d HT nylon Classic Parapack in Olive.

420 denier, high tenacity, type 6.6 nylon fabric was originally developed for the military for use in parachute backpacks — the thing on the guy’s back that holds the parachute. Paratroopers needed a fabric that was smooth so as not to hang up on anything as a jumper left the plane; it had to be light (obviously); and it needed to be strong so as not to be easily punctured or abraded. These same qualities gave it great appeal in the blossoming outdoor-recreation industry; 420d HT nylon became the staple backpack fabric in the early 1960s, almost entirely replacing cotton canvas. At one time, virtually all high-end backpacks were made of 420d HT “Parapack” (short for parachute-backpack) fabric.

In the late 1960s and early 1970s, a renewed interest in health, nature, and the environment coevolved with an interest in self-propelled outdoor recreation: hiking, backpacking, cross-country skiing, even mountaineering, became mainstream pursuits. And pretty quickly folks realized that all their new, light, and durable outdoor equipment functioned just as well back in town as it did in the wilderness. Quilted jackets made of ripstop nylon and filled with goose down appeared on city streets, and small backpacks designed for day hiking became de rigueur on campus. Of course, it wasn’t long before large, corporate (or soon-to-be large and corporate) interests saw the potential in this new market. I’m going somewhere with this, so hang tight.

I’ve already mentioned that 420d HT nylon is light, strong, and smooth, but I didn’t mention what it's not: neither easy to dye, nor cheap. Just like our 1050 denier, high tenacity, type 6.6 ballistic cloth, 420d HT does not take dye as readily as type 6 (or “regular”) nylon. It dyes somewhat inconsistently and often ends up with a slightly heathery appearance (which I’ve grown to really like but can drive our fabric inspectors a bit nuts because it’s not consistent). Lots and lots of daypacks made of 420d HT were sold, and the sellers pushed the fabric mills for something cheaper. Some technically driven, small-time manufacturers wanted quality; some larger companies wanted low cost. Enter 430 denier (type 6 nylon) pack cloth: it was smooth, it was light, it was easy to dye consistently and evenly, and it was considerably less expensive. It was less densely woven, not as strong or abrasion resistant, but price, not quality, was now in the driver's seat.

At about the same time as all that, texturized nylon fabrics (like 1000d Cordura®) were developed as alternatives to both smooth nylon pack cloth and cotton canvas. Their texturized look and feel made them plausible alternatives to cotton canvas, but they were lighter and more durable. The market share for 420d HT Parapack fabric continued to shrink and the mills ran less and less of it, resulting in it being difficult to obtain. Eventually, even high-end manufacturers abandoned 420d HT Parapack.

By the late 1980s, most backpacks were manufactured offshore, and Southeast Asia was making their own Parapack simulacra, with nominal deniers ranging from 400 to 430. Most of it was low quality, none of it high tenacity, but it was cheaper than U.S. made 420d HT. By the 1990s, with U.S. made 420d HT fabric nowhere to be seen, smooth nylon pack cloth became generally equated with low quality products, and understandably so.

Fast forward to 2013: when we went down this nostalgic rabbit hole, looking for fabrics from which to build the new Guide’s Pack and the Founder's Briefcase, we were delighted to find some undyed, unfinished 420d HT nylon in a warehouse on the East Coast. We had it dyed to our own colors and we've pretty much fallen head over heels with it. The mill says they can weave more for us and we hope to add another color or two early in 2014. In addition to our 420d HT nylon Classic Parapack simply being a beautiful, densely woven, tough-as-nails fabric, its smooth surface entirely lacks an affinity for pet hair, lint, sweater fuzz, and snow. Combined with our 1050d HT ballistic fabric in high-wear areas, it makes The Guide's Pack an amazing bag of which we are particularly proud.

And the revival of 420d HT Parapack continues: we've made our Small, Medium, and Large Café Bags, Synapse 19, Synapse 25, 3D Fabric Organizer Cube, and 3D Mesh Organizer Cube available in 420d HT Parapack.