By Brice Minnigh and Nicole Formosa

For people who’ve spent a big portion of their lives traveling the world on bikes, the word 'Ortlieb' is to panniers what 'Kleenex' is to tissues and 'Hoover' is to vacuums. While several brands have developed some pretty functional touring bags over the years, Ortlieb has for decades stood out as the standard-bearer for saddlebags.

While their simplicity and durability have been huge factors in the near-universal praise, the main reason why so many riders have come to rely on them is because they're completely waterproof. And when you're riding for days, weeks, months or years on end in wet weather, nothing is more important to a pannier's existence than keeping the water out–and off survival essentials such as your sleeping bag, down jacket and spare set of dry tent clothes.

This focus on keeping the contents of the bag dry has been Ortlieb's foundation ever since it began making its classic waterproof panniers more than three decades ago. Though updated fastening systems and fresh designs have supplanted the original versions, the basics have remained the same. The manufacturing process, materials and shape have changed very little since Hartmut Ortlieb sewed his first bag in 1982. Then only 18, Ortlieb developed a system for making waterproof bags in his mother's garage after a particularly wet bike tour in the United Kingdom. While pedaling alongside rain-drenched roads, he couldn't help but notice all the trucks passing by, their loads covered in PVC tarps to keep the cargo dry.

When Ortlieb returned to his home in Nuremberg, Germany, he bought a cheap industrial sewing machine and started experimenting with PVC. He found that the sewing needle punched a hole in the fabric with every stitch, so he turned to RF (radio frequency) welding, a process invented in the 1950s as a way to create a union without compromising the waterproof nature of a material.

This technology only worked for two-dimensional materials, however, so Ortlieb began experimenting with 3D welding, which requires a mold and a last that fit perfectly with the bag shape.

"It's like casting a part," says Ian Strakal, the longtime product manager at Ortlieb USA. "The mold has to fit the exact bag shape–you lay the fabrics around the mold and the last has to line up perfectly. It's really tricky to achieve all those goals at once. I can't tell you how we do that because that's the 'secret sauce.'"

More than 30 years later, this is still the technology that Ortlieb uses to make its lightweight panniers and other waterproof bags. The company has since moved to Heilsbronn, Germany, but to this day every part of the manufacturing process remains on one campus. Even the heavy equipment used to weld panniers is machined on site.

Keeping all this trade knowledge in-house helps prevent the threat of cheap knock-offs, ensuring that Ortlieb's 'secret sauce' will continue to keep riders' most important gear dry for decades to come