When it comes to Outdoor Research's outerwear collection, understanding the differences between 3L (3-layer), 2.5L (2.5-layer), and 2L (2-layer) fabrics is key to choosing the right shell for your activity. These designations refer to the construction of waterproof and windproof layers that protect you from the elements. Each system has its strengths and trade-offs when it comes to waterproofing, wind proofing, durability, and comfort, and once you know how we build each version, you'll know precisely which shell to get for your specific use case. 3-Layer (3L) Outerwear Key OR Styles: Hemispheres II GORE-TEX Jacket / Bibs, SkyTour AscentShell™ Jacket / Bibs, Carbide Jacket / Bibs, Headwall GORE-TEX Jacket / Pants, Foray 3L Jacket / Pants, Aspire 3L Jacket / Pants What it is:3L outerwear is the most technically advanced of the three, often used for high-performance gear designed for extreme conditions like mountaineering, backcountry skiing, or long-term expeditions in harsh weather. In a 3L system, the fabric is constructed by sandwiching the waterproof membrane between a durable outer fabric (called the face fabric) and an inner liner. Outer Layer (Face Fabric): This layer is usually a durable material like nylon or polyester, designed to protect against abrasion, tearing, and external elements. Middle Layer (Waterproof Membrane): A breathable waterproof membrane, such as GORE-TEX or Pertex®, is laminated to the outer layer. This membrane is the heart of the system, allowing sweat and vapor to escape while preventing water and wind from getting in. Inner Layer: Instead of a loose lining, 3L garments bond a protective inner layer (often a softer fabric like C-Knit or mesh) directly to the membrane. This adds durability while maintaining breathability. Waterproofing and Wind Proofing:3L jackets offer top-tier waterproofing and wind proofing because of their full construction. Membranes like GORE-TEX and Pertex® are well-known for their microporous structures that block water droplets but allow vapor molecules to pass through, making them incredibly breathable as well. 3L garments are typically rated highly on waterproofing scales, often exceeding 20,000mm (a measure of how much water a fabric can withstand before it leaks). Thickness and Weight:While 3L jackets are more robust, they don't have to be heavy. Advancements in technology allow for 3L designs that are surprisingly lightweight, like those using Outdoor Research's AscentShell™ Dry and AscentShell™ Air technology. However, 3L jackets tend to be thicker and less packable than their 2L or 2.5L counterparts, making them better suited for intense weather rather than casual outings. Breathability:Thanks to innovations like AscentShell™ Air and GORE-TEX Pro with C-Knit technology, 3L jackets often boast superior breathability. The inner layer's soft and smooth fabric allows for better moisture management and next-to-skin comfort. These jackets are ideal for activities where you're likely to sweat, such as alpine climbing or backcountry skiing. 2.5-Layer (2.5L) Outerwear Key Styles: Stratoburst Stretch Rain Jacket / Pants What it is:2.5L jackets provide a middle ground between the durability of 3L designs and the weight and thickness of 2L models. In a 2.5L system, the waterproof membrane is laminated to the face fabric, but instead of a full inner liner, there is a protective coating or print (often called a half-layer) on the inside to shield the membrane from wear and tear. Outer Layer (Face Fabric): Like in 3L jackets, this is typically a durable, water-resistant fabric such as nylon. Middle Layer (Waterproof Membrane): The waterproof membrane is often the same as used in 3L designs (e.g., GORE-TEX or AscentShell™), but the difference lies in the protection of this membrane. Inner Half-Layer: 2.5L jackets use a thin protective coating or print directly over the membrane instead of a full fabric lining. This makes the jacket lighter but slightly less durable over time, especially with heavy use or abrasion. Waterproofing and Wind Proofing:Though 2.5L jackets offer excellent waterproofing, they usually don't match the extreme protection of 3L jackets. That said, they're still very effective in most outdoor conditions, including heavy rain or high winds. Breathability and wind proofing are strong, as the membrane still blocks airflow effectively.Thickness and Weight:This is where 2.5L jackets shine. They are lighter and more packable than 3L jackets, making them ideal for backpacking or long day hikes where weight and bulk matter. The half-layer design cuts down on both the thickness and the overall weight of the garment, though this also means it will be less durable in the long term. Breathability:2.5L jackets are highly breathable, but they tend to feel a little less comfortable directly against the skin compared to 3L models. The protective print or coating can sometimes feel sticky or clammy during high-output activities. However, technologies like Outdoor Research's Ventia™ are improving the breathability and comfort of 2.5L designs. 2-Layer (2L) Outerwear Key OR Styles: Tungsten II Jacket / Pants, Snowcrew Jacket / Pants, Grandridge GORE-TEX Jacket What it is:2L outerwear is the most basic of the three constructions. In a 2L system, the waterproof membrane is bonded to the outer fabric, but the inner lining is a separate, free-hanging layer. This is typically the most affordable option and is great for activities in less extreme weather or casual, everyday wear. Outer Layer (Face Fabric): Similar to 3L and 2.5L designs, the outer layer is usually made of durable nylon or polyester. Waterproof Membrane: A breathable, waterproof membrane like GORE-TEX is laminated to the outer fabric but lacks the bonded inner layer. Inner Layer (Separate Liner): A loose liner, often made from mesh or taffeta, is added inside for comfort and some moisture management. This liner also provides a bit of extra insulation, though it can feel bulky. Waterproofing and Wind Proofing:2L jackets provide reliable waterproofing and wind proofing but are generally less robust than their 3L or 2.5L counterparts. They are effective against rain, snow, and moderate wind but may not hold up as well in long, harsh storms or high-wind environments.Thickness and Weight:These jackets tend to be thicker and potentially heavier because of the loose liner, but potentially warmer because insulation can be added in between the face fabric and inner liner. While not as packable as 2.5L designs, 2L jackets are still a solid choice for activities like cold weather resort skiing, day hiking, or commuting, where packability isn't the highest priority.Breathability:2L jackets are less breathable than 3L or 2.5L designs because the inner liner can trap moisture. They're better suited for lower-intensity activities, where you're less likely to overheat.ConclusionChoosing between Outdoor Research's 3L, 2.5L, and 2L outerwear comes down to the specific demands of your outdoor activities. 3L jackets are the go-to for extreme, high-intensity adventures, offering the best waterproofing, wind proofing, and durability. 2.5L models strike a balance between lightweight performance, weight, and protection, ideal for fast-paced outdoor sports. Finally, 2L jackets are great for cold weather outdoor pursuits, less intense activities, or casual wear, offering reliable protection and insulation without the technical features or price of higher-layer constructions. With innovations like AscentShell™ Dry, AscentShell™ Air, GORE-TEX, Pertex®, Ventia™, and C-Knit, each type offers impressive performance, and understanding the differences will help you make the best choice for your needs.
