Why We Use YKK Zippers on our Bags (and Why It Matters for Long-Term Wear)

We don’t just order components — we talk through them, test them, and ask a lot of questions.

When a handbag doesn’t hold up over time, it’s rarely because of one dramatic failure. More often, it’s a small component that was overlooked early on. With a background in apparel merchandising and textiles and more than two decades designing handbags, I’ve learned that longevity is shaped by a handful of quiet decisions — durable materials, thoughtful construction, and how stress moves through a bag in daily use, or a trip through the washing machine.

One of the most common weak points isn’t always obvious when you’re shopping. It’s usually not the fabric or the shape. It’s the parts that do the most work: hardware, stitching, and the places where movement and weight meet.

Close-up of a YKK zipper pull used on a Crystalyn Kae bag, showing the manufacturer’s mark intentionally left visible as a quality signal.

What are Ykk Zippers? 

In the early 1930s, a young Japanese engineer named Yoshida Kogyo began designing his own zipper machinery rather than relying on existing equipment. He founded Yoshida Kogyo Kabushikikaisha (YKK) in 1934, and that decision—to control the process rather than outsource it—still defines YKK today. Unlike most zipper manufacturers, YKK designs and builds much of its own machinery and produces many of its own materials, including smelting metal for zipper teeth. That level of vertical integration allows for tight tolerances, consistency, and precision—qualities that matter when a zipper is opened and closed thousands of times over the life of a bag.

Why Consistency Matters

YKK’s reputation was built on dependability, not trend cycles. Yoshida believed that making good products required close attention to every step of the process, and that philosophy remains central to the company. By controlling materials, machinery, and production standards in-house, YKK is able to deliver predictable performance over time. From a sustainability standpoint, that reliability matters: components that are responsibly made, traceable, and designed to last don’t need to be replaced as often. For us, choosing zippers that hold up year after year is one of the most practical ways to design for longevity—and longevity is a core part of our sustainability mission.

Why do we use YKK zippers?

Choosing YKK isn’t about branding or trends — it’s about reliability over time. The color choices and custom options on YKK zippers may seem like a rabbit hole to some. But for us, being able to choose the best zipper for each product is part of our commitment to great design. Not only can we choose color, but we can choose the metal, smoothness, zipper pull, and many other features. You didn't know zippers came with so many choices, did you?

Zippers on spools in Crystalyn Kae's workshop

The zippers on our products

You may have noticed that we offer zippers in two main styles — with metal teeth, or nylon teeth. Here are a few reasons we might choose one over the other.

Nylon zippers

Nylon zippers are made from a coiled monofilament, typically nylon. We often choose them when:

• smooth, low-friction movement matters over years of frequent use

• flexibility helps reduce stress on the zipper tape and surrounding fabric

• lightweight construction supports overall bag comfort without sacrificing durability

Metal zippers

Metal zippers are made from individually formed metal teeth and tend to be more rigid. We choose them when:

• structure and resistance to deformation are priorities

• the bag may carry heavier contents over time

• a zipper needs to maintain alignment and strength through long-term use

Detail view of a zipper sewn into a finished bag, highlighting stitch density and clean integration designed for long-term use

Zippers are just one piece of what determines how long a bag lasts. Materials, stitching, construction, and how components work together over time all play a role — and overlooking any one of them can shorten a bag’s lifespan.