It keeps rain out while allowing sweat vapour to escape, but what is GORE-TEX actually made from? The original GORE-TEX membrane was made from expanded polytetrafluoroethylene (ePTFE), a stretched polymer containing billions of microscopic pores. Modern GORE-TEX products can now use either ePTFE or Gore’s newer expanded polyethylene (ePE) membrane, depending on the product.
If you spend enough time outside, you get used to battling the elements and braving the rain. A quality set of waterproofs can make a massive difference when the weather changes unexpectedly, but with so many waterproof fabrics available, it isn’t always obvious what you’re actually paying for.
One of the most common comparisons is GORE-TEX vs eVent, along with the growing number of proprietary waterproof membranes now used by outdoor brands. GORE-TEX has established itself as one of the best-known waterproof technologies in the world, but what exactly is it made from and is GORE-TEX worth the money?
What Is GORE-TEX?
GORE-TEX is not simply one thick waterproof fabric. At the heart of a GORE-TEX product is an extremely thin waterproof and windproof membrane that is bonded to other textile layers to create a laminate.
The membrane prevents liquid water from getting through from the outside while still allowing perspiration vapour to move outwards. This gives GORE-TEX its familiar combination of being waterproof, windproof and breathable.
The classic ePTFE GORE-TEX membrane has more than 9 billion microscopic pores per square inch. Those pores are small enough to block liquid water while still allowing water vapour from sweat to escape.
What Is GORE-TEX Made Of?
The original GORE-TEX membrane is made from expanded polytetrafluoroethylene, normally shortened to ePTFE. PTFE is a synthetic fluoropolymer, and in 1969 Bob Gore discovered that rapidly stretching it created an incredibly strong microporous material.
If you’re wondering what a polymer actually is, Britannica has a good explanation of polymers here. In simple terms, polymers are materials made from long repeating chains of molecules, and their properties can be dramatically altered by changing how those chains are arranged or processed.
Bob Gore’s expanded PTFE contained an enormous network of microscopic pores and became the basis for the original GORE-TEX waterproof membrane. That discovery is what eventually allowed manufacturers to make clothing that could block rain without behaving like a completely sealed plastic bag.
Modern GORE-TEX Can Also Be Made From ePE
This is the major change since the original version of this article was written. GORE-TEX now also uses a newer membrane made from expanded polyethylene, or ePE, alongside traditional ePTFE technology.
The newer ePE membrane is extremely thin and lightweight while still providing waterproof, windproof and breathable performance. Gore introduced ePE into consumer GORE-TEX products from 2022 onwards and has continued expanding its use across the range.
Gore describes current GORE-TEX membranes as generally being a very thin bi-component construction based on either ePE or ePTFE combined with polyurethane (PU). The membrane is then bonded to carefully chosen outer and inner textiles to create the finished laminate.
The newer ePE laminate is particularly interesting because Gore produces it without intentionally added PFAS and says its lower-mass membrane and selected textiles reduce the laminate’s carbon footprint compared with previous constructions.
How Is GORE-TEX Made?
The membrane itself is only part of the finished product. To turn it into a jacket, pair of trousers, gloves or boots, Gore laminates the membrane to different textile layers depending on the intended use.
You will commonly see GORE-TEX described as 2-layer, 2.5-layer or 3-layer construction. These descriptions refer to how the membrane and protective textile layers are combined rather than the number of separate pieces of fabric you can physically pull apart.
2-Layer GORE-TEX
In a 2-layer GORE-TEX construction, the membrane is bonded to the outer face fabric while the inner lining remains separate. This makes it easy for manufacturers to add insulation or a comfortable hanging liner inside the garment.
2-layer construction is commonly used in ski jackets, insulated waterproofs and everyday outerwear where comfort and warmth matter more than achieving the absolute lowest weight.
2.5-Layer GORE-TEX
Some lightweight waterproof garments use what is commonly called a 2.5-layer construction. The membrane is bonded to the outer textile, while a very thin protective print or backer is used on the inside instead of a completely separate fabric layer.
This reduces weight and bulk, which is why you often see 2.5-layer construction in lightweight emergency shells and packable waterproof clothing. The trade-off is that it can feel less substantial against the skin than a full 3-layer laminate.
3-Layer GORE-TEX
In a 3-layer GORE-TEX garment, the membrane is sandwiched between an outer face fabric and a protective inner backer, with all three bonded together into one laminate. This is the construction commonly associated with technical mountaineering shells and rugged waterproof jackets.
Bonding all three layers together creates a relatively compact and durable material because there is no loose inner lining rubbing against the membrane. Modern GORE-TEX Pro products, for example, continue to use this type of 3-layer construction.
Z-Liner GORE-TEX
The original version of this article also mentioned Z-liner construction, and it did genuinely exist. In a Z-liner garment, the membrane was bonded to a lightweight carrier fabric and allowed to sit more independently between the outer fabric and inner lining.
This gave clothing designers more freedom when working with insulated jackets and complicated garment shapes. You don’t see the term nearly as often in modern consumer GORE-TEX marketing, where 2-layer, 2.5-layer and 3-layer constructions are much more prominent, but it remains part of GORE-TEX’s manufacturing history.
Taped Seams
Even the best waterproof membrane stops being completely waterproof if you punch thousands of sewing-machine holes through it and leave them exposed. Garments obviously still need stitching, so waterproof seam tape is applied over those stitched areas.
The tape seals the tiny holes created by the needle and helps turn the laminate into a genuinely waterproof finished garment. Gore doesn’t simply supply membrane material either; approved GORE-TEX products have to meet its wider manufacturing and waterproofing standards.
GORE-TEX membrane under a microscope
How Does GORE-TEX Work?
The classic explanation comes from the original ePTFE membrane. Gore says it contains around 9 billion microscopic pores per square inch, with each pore roughly 20,000 times smaller than a water droplet.
That means liquid rainwater cannot simply pass through the membrane. At the same time, moisture vapour created as your body sweats can move through the laminate and escape, which is what people mean when they describe GORE-TEX as breathable.
It is worth remembering that breathable does not mean air flows through GORE-TEX like mesh. The membrane is designed to move moisture vapour while remaining windproof, and how comfortable it feels depends on temperature, humidity, activity level and the rest of your clothing system.
What Does the DWR Coating Do?
The outer face fabric of a GORE-TEX jacket is normally treated with a Durable Water Repellent (DWR) finish. DWR doesn’t provide the main waterproof barrier — that is the membrane’s job — but it helps rain bead up and roll away instead of soaking into the outer textile.
When the DWR wears down, the face fabric can become saturated or “wet out.” The membrane underneath may still be waterproof, but the soaked outer material makes the jacket heavier, colder and less effective at moving moisture vapour away from your body.
This is why an old GORE-TEX jacket can sometimes feel as though it has stopped working even though the membrane is still intact. Washing the garment correctly and reactivating or renewing the DWR can restore much of its original performance.
Is GORE-TEX Made From Teflon?
You will often see people describe GORE-TEX as being made from Teflon because traditional GORE-TEX and Teflon are both associated with PTFE. The more accurate description is that the original GORE-TEX membrane is made from expanded PTFE, or ePTFE.
Teflon is a trade name associated with a family of fluoropolymer products, so calling the GORE-TEX membrane simply “Teflon” is a useful shortcut but not really the proper technical description.
Is All GORE-TEX Still Made From PTFE?
No. This is probably the biggest change to remember if you’ve read older explanations of GORE-TEX.
Traditional GORE-TEX membranes use ePTFE, and many GORE-TEX products still do. Newer products can instead use Gore’s expanded polyethylene (ePE) membrane, which provides the same core promise of durable waterproofing, windproofing and breathability through a different material platform.
Is GORE-TEX Completely Waterproof?
GORE-TEX products carrying the waterproof GORE-TEX label are designed to be durably waterproof, but the finished product depends on much more than the membrane alone. Seams, zippers, construction methods and the way the membrane is integrated into the garment all matter.
Gore currently says its waterproof laminates consistently exceed a hydrostatic-head standard of 28,000 mm water column. That is more than enough waterproofing for the kinds of rain pressure most outdoor clothing will encounter.
Final Thoughts
So what is GORE-TEX made of? Historically, the answer was simple: expanded PTFE. Bob Gore discovered that rapidly stretching PTFE created the microporous ePTFE material that became the heart of the original GORE-TEX membrane.
Today the answer is slightly more complicated. Modern GORE-TEX products can use either traditional ePTFE or the newer ePE membrane, often combined with polyurethane and bonded to other textiles to form 2-layer, 2.5-layer or 3-layer laminates.
The basic idea hasn’t changed, though. You have an incredibly thin membrane keeping liquid water and wind outside while allowing moisture created by your body to escape. More than 50 years after Bob Gore stretched his first piece of PTFE, it’s still a pretty clever bit of outdoor technology.
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