Since I began my backpacking journey in the 1990s, I have always relied on a trusty lightweight fleece jacket. While the puffers have gained a considerable following and merino wool has emerged as a sustainable, odor-resistant alternative, the classic fleece remains a coveted staple for its durability, breathability, and affordability. In fact, my 30-year-old Marmot fleece jacket still performs like a champ, proving that some things never go out of style.

However, if you've been out on the trails recently, you might have noticed a new wave of high-tech performance fleeces taking center stage. Models like the Patagonia R1, Senchi Designs Alpha 120, and the elusive Melanzana Micro Grid are becoming increasingly popular among climbers and backpackers. But what exactly sets these new fleece varieties apart from the traditional ones? Do you really need to invest in one? Lets explore the various types of fleece available to outdoor enthusiasts today. And if you're keen to dive deeper into outdoor apparel, dont forget to check out our comprehensive guides covering everything from the best rain jackets to the top running shorts.

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The Original Fleece

The story of fleece dates back to the 1980s, a time when it was first introduced to the world by Malden Mills, now known as Polartec. The original fleece fabric quickly gained popularity for its lightweight and versatile properties, making it an ideal choice for various outdoor activities. Over the years, my trusty fleece jacket has proved invaluable during breaks on high mountain passes, especially when temperatures plummet and the wind picks up unexpectedly. While it may not provide the same level of wind resistance as an outer shell, fleece can still keep the chill at bay during those essential hiking pauses. Beyond the trails, its also great for casual wear in town or around the campsite.

Depending on the weather conditions and how much ventilation you need, fleece can serve as a reliable option for aerobic exercises. For instance, a half-zip fleece pullover allows for greater airflow, making it my go-to choice for brisk spring and fall mornings. However, during more intense activities, such as cycling, traditional fleece can struggle to keep up in terms of breathability. Recognizing this limitation, textile manufacturers began exploring new fleece technologies to enhance performance.

Grid Fleece

To address the shortcomings of classic fleece, Polartec developed a new variant known as grid fleece, specifically their Polartec Power Grid. This innovative fabric incorporates about 5 percent elastane (often recognized as Spandex) woven in a grid-like structure, allowing for increased breathability without sacrificing warmth. The strategically designed gaps trap air, providing insulation while also expelling moisture efficiently. Nevertheless, one notable trade-off is that grid fleece is less effective at blocking wind compared to its original counterpart.

Generally speaking, grid fleece is not designed for lounging around camp but rather for active daytime wear. It excels when paired with a lightweight windshirt or rain jacket, making it particularly suitable for high-intensity activities like cycling. Personally, I find that combining grid fleece with my Patagonia Houdini wind shell is perfect for those early morning rides. This duo outperforms traditional fleece in both warmth and breathability while effectively blocking the wind.

Alpha Direct Fleece

In 2017, Polartec took things a step further by collaborating with the US military to develop Alpha Direct fleece, often referred to simply as Alpha. This groundbreaking material is even lighter and more breathable than grid fleece. Alpha fleece employs a unique fishnet weave that holds high-loft fibers within the structure, optimizing both insulation and airflow. Originally intended for military use, where it would be layered under a windproof outer shell, this fleece has since attracted the attention of boutique hiking brands, who have created lightweight fleece hoodies using only Alpha Direct.