Is Pertex Quantum Waterproof? Fabric Names Explained

Quantum Is Water-Resistant; Shield Uses a Waterproof Membrane

Standard Pertex Quantum is water-resistant downproof woven fabric, not a waterproof membrane system. Its surface finish helps shed lighter wetting. Pertex Shield identifies the waterproof membrane family. Quantum Pro, Quantum Air and Shield Air have their own constructions, so read the full name before deciding what a Pertex label contributes to a parka.

You may have two coats open in separate tabs, both advertised with Pertex fabric. One says Pro; the other says Shield. Choosing the supposedly higher word can feel like an easy shortcut. It leaves a basic question unanswered: is the fabric there to contain insulation, allow useful airflow or form a waterproof shell?

The manufacturer’s current fabric range separates those constructions. Use the full names in the table to find the fabric your coat uses; Pro and Air are not steps on a single cheapest-to-best scale.

These are manufacturer-described fabric roles, checked November 2, 2026. A fabric family is one part of a complete parka. The coat still has its own filling, seams, openings, fit and intended use.

Quantum Pro Adds a Coating, Not a Universal Waterproof Promise

Quantum uses a fine, tightly woven construction to make a soft, downproof fabric that accommodates insulation loft. Downproofing concerns retaining filling within its fabric envelope. It is a different job from resisting liquid water under pressure.

A DWR finish helps the face shed lighter wetting. That is useful protection for an insulated garment, but it does not turn the whole Quantum family into a waterproof membrane system. “Down jacket with Pertex” is therefore an incomplete rainwear description.

Quantum Pro adds a microporous coating to a tightly woven face. Pertex describes the result as highly water-resistant while retaining low weight, softness and breathability. That explains the practical distinction from the basic woven construction. It is more precise than treating Pro as a universal quality grade.

Shield is a different system: woven face fabric, membrane and an optional backing layer, offered in different combinations. Its 2L, 2.5L and 3L arrangements concern the waterproof fabric system. They do not tell you how many warm clothing layers are inside the coat.

The illustration separates a repellent surface from a barrier and from the protection of a join.

On a Quantum Pro coat described as weather-resistant, a coating does not by itself promise protection for a sustained rainy walk. On a Shield garment sold as waterproof, look for how the seams and openings complete the shell. Read the whole garment description alongside the fabric name.

Neither category makes filling quantity irrelevant. A light uninsulated Shield rain jacket and a down-filled Quantum Pro coat serve different thermal roles. The water-resistant versus waterproof guide explains the broader weather claims; the full family name tells you which textile construction you are starting with.

Quantum Air and Shield Air Solve Different Problems

The word Air appears in both names, but the constructions are different. This is where matching the suffix alone produces a particularly misleading comparison.

Quantum Air: airflow through a woven fabric

Pertex describes Quantum Air as an open-woven construction whose air permeability and wind resistance are engineered for the intended use. It is used in active insulated layers and lightweight windshells. Controlled airflow can be useful when movement produces heat and moisture; stopping every possible movement of air is not the only design objective.

That does not assign the same airflow to every Quantum Air fabric. The family contains variations. It also does not make the fabric a waterproof membrane merely because another name in the supplier’s range includes Air.

Shield Air: an air-permeable waterproof membrane

Shield Air uses an electrospun nanofibre membrane. Pertex describes an interconnected porous structure that allows air and moisture vapour through while providing a barrier to liquid water. This is a membrane construction, rather than Quantum Air’s open weave.

Air permeability and moisture-vapour transfer are related to different measurements: one concerns air passing through, while the other concerns water vapour. A fabric described as breathable need not have the same airflow as a windshell. Comparing only a large breathability number can miss the physical distinction.

For the buyer, the useful result is straightforward: Quantum Air belongs in the active-layer or windshell conversation; Shield Air belongs in the waterproof-fabric conversation. The rest of the selected garment determines whether either suits the trip. Neither name guarantees that a heavily insulated coat will feel comfortable during every climb or warm indoor stop.

One Jacket Can Use Pertex Outside and Inside

The supplier’s name may appear more than once in one garment. That does not mean the specification contradicts itself. The fabrics can occupy different positions and perform different jobs.

Rab’s current Men’s Neutrino Pro Down Jacket, QDB-85, lists the following components. These are that model page’s disclosures checked November 2, 2026, not a description of every version sold under a similar name.

In this jacket, Quantum Pro forms the outside, Quantum forms the lining and down sits between them. The lining’s higher listed fabric mass does not make it the stronger rain barrier. Grams per square metre tells you mass per area; the coating and position explain a different part of the construction.

Notice the two different uses of Pro as well. Neutrino Pro is the garment name; Quantum Pro is the named outer fabric. The garment name cannot be applied to every material within it. Reading the individual component lines is what resolves that apparent ambiguity.

If a listing says only “Pertex construction,” look for the fabric named for the outside of the jacket, then read the lining and filling separately. A Pertex lining can sit inside a shell made from something else. Ask about that shell if the description does not name it.

Choose for the Weather Role Before the Suffix

Start with the problem the coat has to solve, then use the family information to build a relevant shortlist.

• Insulation for cold conditions with limited wet exposure: a downproof woven outer can be a sensible part of the garment. Quantum or Quantum Pro may appear here; compare the actual filling, coverage and described weather role.
• Repeated liquid rain as well as cold: seek a documented waterproof garment or a suitable separate shell system. Shield is a relevant fabric family to investigate, with the selected coat’s seam and opening construction.
• An active layer or light windshell: controlled airflow may be a benefit. A Quantum Air garment can belong in this comparison without being a replacement for a warm, stationary winter coat.

Those branches explain why there is no universal winner. A waterproof membrane is valuable when its role is needed. It does not automatically give the preferred drape, sound, low weight or heat management for every everyday outing. Conversely, a comfortable light outer cannot supply an undocumented rain barrier.

Once the coat suits the weather you expect, try it over your normal layers. Check shoulder movement, the hood as you turn your head and the lower front while seated. Use the shell-fabric buying guide to compare weave, weight and feel between otherwise suitable coats.

Follow the coat maker’s washing and drying instructions. Two garments with the same Pertex family can have different linings, filling or fixed fur trim, so they may need different care. Do not copy an iron setting or treatment from the fabric name alone.

Questions About Pertex Parka Fabrics