It’s Gore-Tex, that magical material from which expensive waterproof jackets are made!

Strictly speaking, it is not ONE material, but an entire series of different layers of fabric with specific specifications. What they all have in common is a specific form of polytetrafluoroethylene (say that 3 times fast if you dare!), PTFE or Teflon to its friends.

What’s so amazing about this material?  It allows water vapor to pass through it, but blocks liquid water. In other words, it is waterproof AND breathable!

Doesn’t sound that amazing to you? Try wearing a nylon bag. You may not get wet from the rain, but in a few minutes you’ll be soaked from your own sweat!

The inventors of Gore-Tex were William and Robert Gore, father and son. Legend has it that the discovery was made by accident, thanks to the son’s sensitive nerves. While he was struggling with PTFE, frustrated by his previous failures, he stretched the material forcefully.

The result was that this plastic stretched by 8 times and also acquired these magical properties. On a microscopic level, you see, with this deformation, the structure of the material changed, forming crystalline regions.

This is also why manufacturers of Gore-Tex jackets tell you not to expose them to high temperatures: heat restores the material’s microscopic structure to its original state...