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Fabrics and waterproofing

Cordura

Also called Cordura nylon

What is Cordura?

Cordura is a brand of high-tenacity nylon fabric known for abrasion resistance, used where a pack meets rock and grit. It is a specification a mill licenses rather than a single fabric, so Cordura appears in weights from light shelter cloth to heavy pack bottoms.

Cordura at a glance

Light pack body
100D to 210D
Pack bottoms
500D to 1000D
Fiber
High-tenacity nylon
Standard it beats
Abrasion, not tear

What the name guarantees

Cordura is a brand applied to fabrics that meet the licensor's specification, not a single material. The common thread is high-tenacity nylon yarn and a mill held to a durability standard, which is why the name carries real information about abrasion resistance where an unbranded nylon carries none.

It is not one weight. Cordura appears at 100D in light pack bodies and at 500D or 1000D in bottoms and military kit, and the difference between those is far larger than the difference between Cordura and a good unbranded nylon at the same denier. Read the number, then the name.

Abrasion is not the same as tear strength

High-tenacity nylon resists being rubbed away, which is what happens when a pack is dragged across granite or set down on gravel a few hundred times. That is a different failure from tearing, which is about a concentrated load, and a different one again from puncture.

Which matters depends on how you use a pack. A scrambler wearing through the base wants abrasion resistance. Someone snagging their pack on branches wants a ripstop grid and tear strength. Most decent packs address both by using a tougher fabric on the bottom panel than on the body.

What this means when you're choosing

  • The denier next to the name, which tells you far more than the name alone
  • A heavier fabric on the bottom panel than on the body
  • Whether it is a ripstop Cordura, if snagging is your failure mode rather than scuffing

The common mistake

Reading the name as a single quality tier

A 100D Cordura pack body and a 1000D Cordura base are both Cordura and are not remotely comparable. The brand tells you the yarn is high-tenacity and the mill is held to a standard. The denier tells you what the fabric will actually survive.

Common questions

Is Cordura waterproof?

No. It is an abrasion-resistant nylon. Any water resistance comes from a coating applied to it, usually polyurethane, or from a separate liner.

Is Cordura always better than plain nylon?

At the same denier, generally yes for abrasion, because the yarn is high-tenacity and the mill is held to a spec. Across different deniers the comparison stops meaning anything: a 1000D unbranded nylon outlasts a 100D Cordura easily.

Where this is defined

Where this comes up

Guides on Tom's Hiking where cordura changes which product is right for you.

More in fabrics and waterproofing

DWR

DWR is a chemical finish applied to the outside of a rain shell so water beads up and rolls off instead of soaking into the face fabric. It wears off with use and washing, and reviving it is routine maintenance rather than a repair.

Waterproof-breathable membrane

A waterproof-breathable membrane is a thin film bonded inside a shell fabric with pores small enough to block liquid water but large enough to pass water vapour. It's what makes a rain jacket different from a plastic poncho.

Gore-Tex

Gore-Tex is a brand of waterproof-breathable membrane made by W. L. Gore & Associates, and the name most people know the technology by. Gore licenses it to clothing makers under strict construction rules rather than selling finished garments.

ePTFE

ePTFE is expanded polytetrafluoroethylene, the microporous film at the heart of the original Gore-Tex and several competing membranes. Stretching PTFE creates billions of pores per square inch that block liquid water and pass vapour.

Hydrostatic head

Hydrostatic head measures how much water pressure a fabric holds before it leaks, expressed as a column height in millimetres. A 20,000 mm rating means a 20-meter column of water sat on the fabric before the first drops came through.

MVTR

MVTR measures how much water vapour passes through a fabric in a day, given in grams per square meter per 24 hours. Higher numbers mean a more breathable fabric, with most hiking shells landing between 10,000 and 25,000.

RET

RET measures how much a fabric resists the evaporation of sweat, tested under ISO 11092. It runs the opposite way to most ratings: lower is better, with under 6 counting as extremely breathable and over 20 as barely breathable at all.

Wetting out

Wetting out is when a shell's outer fabric absorbs water instead of shedding it, because the DWR finish has worn off. The membrane still blocks rain, but breathability collapses and the jacket feels like it's leaking from the inside.

Seam tape

Seam tape is a waterproof strip heat-bonded over the stitch line inside a garment or tent. Every needle hole is a hole in the waterproofing, so a shell with an untaped seam leaks there regardless of how good the fabric is.

2L, 2.5L and 3L laminates

These describe how many layers are bonded together in a shell. 2L has a loose liner hanging inside, 2.5L prints a protective pattern straight onto the membrane, and 3L bonds a fabric backer to it. Durability and next-to-skin feel go up with each step.

Denier

Denier is the weight in grams of 9,000 meters of a yarn, written as a number followed by D. It describes how thick the individual threads are, so higher denier usually means a heavier, tougher fabric, though weave and material matter too.

Dyneema Composite Fabric

Dyneema Composite Fabric is a non-woven laminate of UHMWPE fibers sandwiched between polyester films. It is waterproof from the moment it is made, does not stretch or sag when wet, and is the lightest shelter material in common use, at several times the price.

Ripstop

Ripstop is a weave with thicker reinforcing threads laid in at regular intervals, forming the faint grid you can see on tent and pack fabric. The grid does not stop a tear starting, it stops one that has started from running across the whole panel.

Silnylon

Silnylon is ripstop nylon impregnated with silicone on both faces, the standard fabric for lightweight tents and tarps. It is strong and cheap for its weight, and it stretches when wet, which is why a silnylon shelter sags overnight and needs retensioning.

PU coating

A PU coating is a polyurethane layer applied to the inside of a tent, pack or stuff sack fabric to make it waterproof. It is cheap, takes seam tape well and is what most budget shelters use, and it breaks down with age in a way silicone does not.

Softshell

A softshell is a stretchy woven fabric with a brushed or knitted backing that blocks wind and sheds light rain while still breathing hard. It replaces a rain shell on cold, dry, windy days and is the standard fabric for technical hiking pants.

Base layer

A base layer is the garment worn directly against your skin under everything else. Its job is moving sweat off your skin so it evaporates somewhere other than on you, which is why warmth is a secondary consideration and cotton is disqualified.

Merino wool

Merino wool is fine-diameter wool from Merino sheep, spun for next-to-skin clothing at roughly 17 to 19.5 microns. That fineness is what stops it prickling, and it brings odour resistance and warmth when damp at the cost of abrasion life.

Fabric weight (gsm)

Fabric weight in gsm is the mass of one square meter of the cloth, in grams. On a base layer it is the single number that sets the temperature window: about 150 gsm for warm weather, about 200 gsm for three-season hiking, 280 and up for cold.

UPF

UPF, or Ultraviolet Protection Factor, rates how much ultraviolet radiation a fabric blocks. A UPF 30 garment lets about one thirtieth of the UV hitting it through, so it blocks roughly 96.7 percent; UPF 50 lets one fiftieth through, or 98 percent.

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