Testing Páramo Analogy Waterproof Clothing: How Well Does It Work for Rain (and Wind Shells)?

Introduction

Páramo is an English outdoor clothing manufacturer in business for over 30 years. Their clothing claims to be waterproof and highly breathable without using membranes. Páramo gear has been a source of curiosity and possibly skepticism for years. If you search Páramo on Backpackinglight.com, more than 350 results spring up.

Paramo Clothing

Conventional waterproof-breathable fabrics often trap condensation during exertion, leading to discomfort and compromised thermal regulation in cold or wet environments. Páramo addresses this by using directional fabric systems, which actively transport liquid water - not just vapor - away from the body. This approach is designed to maintain a dry microclimate next to skin during high-output activity and persistent precipitation, potentially outperforming traditional membrane-based systems across a wider variety of environmental conditions.

See it at Paramo

I, too, have shared that curiosity, but until recently, I had never seen one.

A few months ago, I received a PM from a member who owned a heavily used Páramo Analogy jacket that he no longer needed and asked if I would test it. He had some specific questions he wanted answered, and I wanted to know if it worked as claimed, so I agreed.

I received the jacket, and it was genuinely well and heavily used. It had some stains, some holes, and tears. I patched the tears. I then washed the jacket in Nikwax Techwash and treated it with Nikwax TX Direct, following the manufacturer’s instructions.

I then proceeded with my usual battery of tests, followed by some tests I created to evaluate its waterproof performance.

What did I find?

The performance of this jacket demonstrates that Analogy’s two-layer construction provides nearly waterproof performance in conditions that substantially exceed Páramo’s test procedure. The tests conducted here concentrated on the fabric’s performance and did not include jacket details such as zippers and the hood. The test did not evaluate how wearing a backpack over the jacket might impact its waterproof performance. Based on the test results, I expect that if one follows Páramo’s recommendations for washing and reproofing, the Analogy jacket will keep you dry through a wide range of conditions. Although I have never worn one of these jackets, I expect it to do as well or better at moisture management than many membrane jackets.

The performance of this jacket raises questions about our reliance on Hydrostatic Head testing to measure garment water resistance. Using both Rain tests and Hydrostatic Head tests can provide a more comprehensive and nuanced understanding of garment performance in wet conditions.

Jacket Description and Standard Test Performance

The Fabrics

Analogy fabrics were developed by Nikwax and are used to create Páramo’s waterproof jackets.

The Analogy jackets are two-layer garments.

The outer shell is a very tightly woven nylon microfiber with tiny voids at the crossings of the weave. This construction will permit reasonable vapor transfer while providing an effective wind barrier. Figure 1 illustrates the construction.

The inner layer is a polyester knit called the “Pump Liner.” The Pump Liner is a thin fabric with a very loose, airy knit that provides some warmth and minimal resistance to vapor transfer. The inner face is lightly napped, providing a little fleece. The construction is seen in Figure 2.

Both layers are treated with Nikwax DWR to provide very hydrophobic performance. The Nikwax DWR and two-layer construction are critical to the functioning of this garment.

Jacket Standard Measurements

• Model: Unknown, it is labeled as 618142
• Size: Women’s Medium
• Weight: 16.8 oz (473 g)
• Air Permeability (Two Layers): 5.6 CFM/ft2
• Hydrostatic Head (Two Layers): 210 mm H2O
• MVTR: 2720 g/m2/24 hours

According to the test results, the jacket’s performance is similar to that of many wind shells. However, owing to the pump liner, robust fabrics, and extensive feature set, it tends to be heavier and bulkier than most wind shells. It has a far lower hydrostatic head than garments typically expected to be waterproof.

What is Waterproof?

Waterproof performance is ill-defined. EN343, a European Standard for Waterproof and Breathable Protective Clothing, provides a definition. EN343 offers two classes of waterproof performance: “Intermediate” at a hydrostatic head greater than 815 mm H2O and “Highest” at a hydrostatic head greater than 1325 mm H2O.

These ratings are highly dependent on usage. If you sit in a puddle or slide down wet snow with clothing rated at 1325 mm H2O, water penetration of the garment will likely occur.

The performance of the Páramo jacket would not be considered waterproof by the EN343 definition because its hydrostatic head is far below the standard’s requirements. This begs the question, does the EN343 definition apply to a jacket with the construction and anticipated utilization of a Páramo Analogy jacket?

How Much Pressure Is Exerted on a Jacket by Falling Rain?

Hydrostatic Head (HH) testing is the primary measure of water resistance for a garment or a tent. HH testing measures the force of a water column pushing against a fabric. The HH test measures static force. The force of an increasing column of water expands the spacing between yarns until the spaces become large enough to let three drops of water pass through.

Figure 3 illustrates the extent of fabric expansion produced by the hydrostatic head test:

In the right image of the HH test, we see that the test fabric is greatly deformed under the test pressure. This expands the spacing between the yarns, forcing water drops through the newly enlarged spaces.

This is not what happens to a jacket in the rain since the occupant of the jacket limits the expansion of jacket fibers. It is unclear how well the hydrostatic test can mimic the forces withstood by a fabric, except to say that a higher test result means it will be harder for water to penetrate. We can estimate how much HH is required for a given pressure, such as kneeling on a tent floor pitched on wet ground, but how do we estimate how much HH is necessary to resist a raindrop?

The force of a raindrop hitting fabric is very different from kneeling in a puddle of water. A falling drop of water, 0.5mm to 5mm in diameter and traveling at a terminal velocity of 2-9 m/s (4.5-20 mph), comes to a virtually instantaneous halt when it hits the fabric surface. The drop then changes dramatically as it deforms and distributes its force over an increasingly large fabric area.

This dynamic force of a raindrop striking a garment differs greatly from the static force of a water column measured by the HH test.

In writing this article, I made a considerable effort to quantify the force of falling rain on a garment. Using ChatGPT-4o and several academic sources, I relied on an iterative process to understand the issue and provide a range of expected values. As part of this process, I developed a pressure measurement technique as part of performing a rain simulation test.