A Quick Guide to UPF Ratings
Learn how protective UPF clothing can help keep the sun’s harmful rays at bay.
Introduction
High-intensity UV rays can be harmful to skin—and sunscreen can rub or sweat off. But wearing sun-protection or UPF clothing can help protect your skin from damaging UV rays all day without needing to re-apply sunscreen.
There’s no such thing as completely sunproof clothing, but we make durable 40+ UPF sun-protection clothing that blocks at least 97.5% of UV rays—and UV protection means you can stay outside longer. Our sun-protection gear is comfortable and durable, from lightweight men’s and women’s sun shirts to trail pants to full-coverage hoodies. Here are the basics of sun protection, including the UPF rating system and how UV-blocking clothes work.
What Does UPF Stand For?
When you spend too much time under the sun, harmful ultraviolet (UV) rays can cause sunburn, skin cancer and other health problems.
UPF, which stands for Ultraviolet Protection Factor, represents the level of UV protection a garment provides while you’re wearing it. A UPF treatment applied to a fabric or garment increases the ability of the material to prevent skin-damaging UV radiation from getting through.
How UPF Ratings Work
The UPF rating of a garment measures the amount of UV light that passes through the fabric and reaches your skin. The higher this number, the better the UV protection. If you want to measure the sun protection a certain UPF rating indicates, divide 1 by the numerical UPF value to find the minimum level of protection. For example, a rating of 40+ UPF means that only 1/40 (or 2.5%) of UV rays can penetrate the fabric, so our 40+ UPF clothing blocks at least 97.5% of UV rays.
What Is UPF Clothing?
UPF clothing is sun-protective clothing made from materials that have been tested and assigned a UPF rating. These garments must also meet minimum coverage requirements for sun protection. Reliable UPF-rated garments are essential, especially in high-UV conditions or environments that increase exposure to UV radiation (like fly fishing in the tropics, hiking at higher elevations or spending time in the water or snow).
We make lightweight, breathable 40+ UPF protective clothing and gear for men, women and kids for use in the sun where dependable UV protection is critical. Many of our sun-protection shirts and other sun-resistant clothes are moisture-wicking and quick-drying to keep you comfortable in and out of the water and on hot or humid days. Hardworking yet easy-wearing UPF-rated gear helps protect your skin without restricting movement. Whether you’re fly fishing, hiking or sliding down snow, consider adding sun gloves, high-coverage sun masks and multifunctional wide-brim hats that shield your head to your kit.
UPF Clothing Materials
Certain fabrics are better than others at blocking UV rays. Thick, tightly woven fabrics made from synthetic materials like polyester and nylon typically make the most effective UPF clothing. Many of our UV-blocking clothes are made with recycled synthetics, but some are made with modal fabric that comes from beech tree pulp. Each garment is durable and built for all-day comfort outdoors.
Some UPF clothing helps block UV rays through the application of skin-safe, lightweight additives to the yarn while others use special constructions or heavier fabrics.
UPF by Construction
UPF by construction means the fabric is intentionally crafted with specific fibers and a knit or weave engineered to provide lasting sun protection. The denser the knit, the less UV radiation can make it through. This also means less airflow.
With the introduction of Capilene® Cool Sun garments in spring 2026, we achieved 40+ UPF that doesn’t rely on added UV chemical treatments but still maintains the breathability and fast-drying performance required by surfers, climbers, runners, anglers and cyclists. This protection remains effective for the lifetime of the garment and advances our commitment to reducing unnecessary finishes across the collection.
UPF by Topical Treatment
UPF by topical UV chemical treatment refers to sun protection applied to the fabric through a chemical finish or coating. This method can boost UPF ratings but may gradually reduce with repeated washing and wear. While this remains a trusted solution throughout the industry, and some of our products still use this approach, we’re actively transitioning toward UPF by construction for lasting protection and fewer added chemistries.
SPF vs. UPF: What’s the Difference?
SPF (Sun Protection Factor) and UPF (Ultraviolet Protection Factor) are both standards that measure UV protection, but they’re two different things. Sunscreen, which is also called sunblock or sun cream, is applied directly to the skin and helps protect it from sunburn. An SPF rating measures the effectiveness of the sun protection you get from sunscreen until re-application. A UPF rating measures the effectiveness of the sun-protective fabrics in clothing. With UPF protection, the skin that’s covered is shaded from the sun until you remove the garment. Keep in mind that when UPF clothing becomes wet or is stretched, it can become less effective.
UPF and SPF work well together. When your goal is all-day UV protection, consider using sunscreen and wearing 40+ UPF clothing.
