What Is Silnylon?

Last Updated on 15/10/2023


In this article, we answer the question, what is silnylon? You will learn how it is made and what makes silnylon an ideal material for outdoor gear, including tents, tarps, bags, backpacks, and kites.

What Is Silnylon?

Silnylon is a lightweight, waterproof fabric known for its versatility and strength in outdoor gear. Short for “silicone-impregnated nylon,” it combines the durability of nylon with the water-resistant properties of silicone. In this article, we explain what makes silnylon an ideal material for various applications, including tents, tarps, bags, backpacks, and kites.

The manufacturing process involves coating a thin nylon fabric with liquid silicone on both sides. The end result is a material that is tough yet lightweight and waterproof. Some outdoor gear brands like Hilleberg use triple-coated silnylon for three times the protection.

However, I have recently learned that silnylon is hydrophilic, which means it can absorb water and is the reason why it can become more stretchy when wet. This is most visible when used for things like tents and tarps, which sag a little when exposed to heavy rain. To fully understand what silnylon is, let’s start by looking at the base materials.


Siliconized Nylon: Fabric Overview

Silnylon specifically uses nylon as the base material. You can also get silpoly and other variations, but here we are just focusing on nylon.

Nylon Origins

Nylon is a synthetic polymer, first commercially produced by DuPont in 1938, that consists of a long chain of amide linkages. Known for its exceptional strength, elasticity, and resistance to abrasion and chemicals, nylon is extensively used in a multitude of applications ranging from textiles, such as stockings and parachutes, to automotive components and industrial gears.

Nylon was initially developed during World War II as a substitute for silk in parachutes, and it has since evolved into various applications. Today, you can find nylon being used in numerous products, from clothing and accessories to outdoor gear like tents and backpacks.

It can be used to make heavy-duty fabrics as well as some of the world’s thinnest and lightest. In most of our articles, we talk about dernier, which is a unit used to describe the thickness of materials like nylon.

How is Sil-Nylon Made?

To start with, you need the base material of nylon, which is probably still on a roll at this point. The first step in creating silnylon is the siliconization process. In this phase, a liquid silicone solution is prepared to be applied to the nylon fabric. This is a special blend of silicon designed for this specific purpose (you can’t use shop-bought silicone).

I cannot find any information anywhere about whether this is sprayed, applied by rollers, or dipped. However, it is clear that it gets applied to both sides of the material, and the bond is permanent. The silicone is absorbed into the nylon and is not like a laminate coating you find on older waterproof fabrics.


Silnylon Vs Silpoly Vs Dyneema

Silnylon, silpoly, and Dynema are all very similar with slightly different characteristics. Here are some of the differences:

Silnylon vs. Silpoly

Silpoly, short for silicone-coated polyester, is another waterproof material used in outdoor gear material. This fabric retains the waterproof characteristics of polyester while adopting a silicone coating the same as silnylon.

When comparing Silnylon to Silpoly, the key differences lie in their base materials. While both are waterproof, Silpoly is less prone to sagging when wet, whereas Silnylon may stretch slightly when exposed to moisture. However, the elasticity of Silnylon can provide better tear resistance compared to Silpoly. Additionally, Silnylon tends to be slightly lighter than Silpoly.

The choice between Silnylon and Silpoly will depend on your specific requirements, whether you prioritize minimal sagging or want additional tear resistance.

Silnylon vs. Dyneema (DCF)

Dyneema Composite Fabric (DCF), formerly known as Cuben Fiber, is another popular option for lightweight outdoor gear. The primary advantages of DCF over Silnylon include its increased strength-to-weight ratio and that it is highly water-resistant.

However, there are some downsides to DCF. Firstly, it is typically more expensive than Silnylon and Silpoly, which can be a factor for budget-conscious users. Secondly, DCF may be more prone to punctures, while Silnylon’s elasticity could provide better overall tear resistance.

ultra sil nylong

Unique Properties of Silnylon

By now, you probably know the main benefits of silnylon, but here they are again, along with one or two downsides.


One standout property of silnylon is its weight. As an ultralight material, it enables you to minimize the overall weight of your gear without compromising on performance. This is especially crucial for thru-hikers and backpackers looking to cover long distances with minimal loads.


Silnylon is also well-known for its waterproof capabilities. This fabric is coated with a thin layer of silicone, making it impervious to water and ideal for use in wet conditions. However, it’s essential to note that silnylon is non-breathable due to its water-resistant nature. This means that moisture or condensation can build up inside your shelter, requiring proper ventilation.

Low Friction

Another characteristic of silnylon is its slippery surface, which is due to the silicone coating. While this property might make the fabric challenging to handle, it adds to its appeal as it allows the material to glide across other surfaces easily.


In terms of strength, silnylon is quite durable, providing excellent tear strength and resistance to wear and abrasion. However, it’s not immune to damage, and proper care should be taken when using it in outdoor applications.

Downsides of Silnylon

One downside to silnylon is its tendency to stretch when exposed to water. Being hydrophilic, it absorbs water and becomes stretchier, leading to sagging in wet conditions. It’s essential to use tensioners or adjust your shelter setup accordingly to maintain the shape and function of your gear.

Lastly, it’s important to consider the effects of UV rays on silnylon. Prolonged exposure to sunlight can weaken the material, so it’s important to protect your gear by pitching it in the shade whenever possible.

sil-nylon poncho

Uses of Silnylon for Camping and Backpacking Gear

Silnylon can be used in many industries, from household items to plumbing and building. But we are an outdoor gear website, so let’s just look at the camping and backpacking industries.

Silnylon in Camping Gear

Silnylon is used for camping gear all the time due to its lightweight, waterproof, and durable properties. It’s commonly used in making tents, tarps, dry sacks, bivy bags, and other types of waterproof gear. Silnylon tents offer a lightweight alternative for backpackers and hikers, providing protection from the elements without adding too much weight to their gear. Tarps made from silnylon can serve as versatile shelters or groundsheets for protecting the underside of your tent.

Silnylon in Backpacking

Backpacking enthusiasts often prefer gear made from silnylon because it’s lightweight yet strong. It’s a popular choice for constructing backpacks, stuff sacks, and even sleeping pads. Backpacks made from silnylon are ideal for adventurers who want to cut down on their pack weight while still ensuring durability.

Stuff sacks are essential for organizing your gear, and silnylon is a preferred option due to its water resistance and lightweight properties. The Sea to Summit Dry Sacks I use all the time are made of silnylon, and I highly recommend them.

If someone asks you what is silnylon? You should now be able to easily explain that it is just nylon treated with silicone to make it waterproof and increase its durability.

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This article has been written and/or edited by Andrew N. 20+ years of hiking, mountaineering, and camping experience, with access to all the latest outdoor gear.

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