The most reliable sun protection you can wear, no reapplication necessary 


What is UPF?

UPF stands for Ultraviolet Protection Factor. UPF measures how much of the sun’s broad spectrum ultraviolet radiation is blocked by a fabric before it can reach your skin. UPF50+ is the highest possible rating on the UPF scale and means that at least 98% of the sun’s UVA and UVB rays are not able to reach your skin, with the fabric acting as a barrier. Thus, UPF rated fabrics are highly effective at preventing sun damage and protecting your skin. 

How is it different from SPF?

Conceptually, UPF and SPF are the same; they both protect you and your skin from the sun’s harmful rays - just in different forms. UPF is the protection rating given to fabrics, while Sun Protection Factor (SPF) is the rating given to topical sunscreen products (lotions, liquids, sprays and solids sunblocks). 

That said, SPF is often misused by consumers leading to inconsistent and unreliable protection. All SPF’s require reapplication at least every 80 minutes depending on activity levels, while UPF provides consistent and reliable coverage throughout the day. 

Unlike UPF, only some sunscreens (SPF’s) provide broad spectrum UVA/UVB protection. 

For that reason, according to the Skin Cancer Foundation, the best way to protect your skin from harmful rays is by wearing UPF rated clothing.  

Why do I need UPF rated fabric? Isn’t all clothing sun protective? 

Not all clothing provides adequate sun protection and people are routinely exposed to the sun’s harmful rays through their regular clothing. Skin cancer is due to the accumulation of sun exposure, so to be continually exposed to the sun without realizing it can be very dangerous.

The average white cotton T-shirt only provides a UPF rating of 5-7 when dry and about UPF 3 when wet. This allows about 1 out of 3 UVA/UVB rays to penetrate your skin and leaves you unprotected against sun damage. That said, some fabrics like denim have a very high UPF rating given the nature of their weave and can block 100% of the sun’s rays, but isn’t always the most comfortable or appropriate choice for outdoor activities. 

Do I only need to worry about sun damage to my face? 

No. To avoid skin cancer and premature signs of aging, it is crucial to protect your whole body, not just your face. In fact, 97% of your skin is below your chin. 

Though people often think that their face will show signs of aging faster than any other part of their bodies, according to a study published by the journal, Genome Biology, the part of your body that ages the fastest is actually the chest, with sun exposure playing a major role in this acceleration. When thinking about sun protection, never forget your chest, hands, neck, elbows or knees. 

What to look for when shopping UPF?

The higher the UPF rating, the greater the sun protection. 

How are your UPF ratings tested and verified?

We work with independent third party laboratories that test to the standards set forth by the American Association of Textile Chemists and Colorists (AATCC 183). Click here to learn more about the AATCC 183 testing protocol. 


Factors that enhance UPF performance

  • Construction: A dense, tight construction of the fabric will block more UV light 
  • Color: Darker, more saturated colors provide more protection than light, paler colors 
  • Treatments: Chemicals UV filters can be added to fabrics to enhance their protective qualities 
  • Fiber type: Polyester and nylon are highly effective at blocking UV light, while cotton is minimally effective

Factors that reduce UPF performance:

  • Fabric wetness: Wetness can significantly reduce a fabric's UPF performance, especially for textiles made of natural fibers. However, certain synthetic fibers like polyester, have been shown to be more effective at blocking the sun’s rays when wet 
  • Fabric wear: The UPF rating of worn or faded pieces can diminish over time
  • Fabric stretch: Fabric that is overly stretched will undermine its UPF performance. 

Garment care and its impact on UPF performance. Can UPF properties wash out?

UPF properties can be achieved in a fabric in two ways: inherent or chemical. Inherent UPF means that the structural properties of the fabric ie. the way the yarn is knit or woven together, provides protection from the sun and blocks the harmful UVA/UVB rays from reaching the skin. For example, denim is inherently sun protective, but not always an appropriate or comfortable choice for outdoor activities. So long as the integrity of the fabric is maintained and it doesn’t have tears or holes in it, the protective quality of the fabric can’t wash out. 

Chemical UPF is when a fabric is treated with a topical chemical UV filter (similar to sunscreen). Chemical UV filters may degrade over time with continued washing and/or exposure to the sun. As with inherent UPF, chemical UPF fabrics that are overly stretched or develop holes will no longer provide sun protection in those areas. 

Follow care instructions to prolong and maximize the life of the apparel. As with all products, the effectiveness of the apparel may degrade over time. 

Do I still need to wear sunscreen when wearing UPF clothing?

If you have any skin exposed, yes. As much of your skin as possible should be protected with a combination of clothing, hats, broad spectrum SPF and SPF lip balm, as UV rays can reflect off of different surfaces such as the ground, water and/or snow. 

What are UVA and UVB Rays?

Two types of UV light are proven to contribute to the risk for skin cancer and have harmful impacts on the skin:

  • Ultraviolet A (UVA) has a longer wavelength. It is associated with skin aging.
  • Ultraviolet B (UVB) has a shorter wavelength. It is associated with skin burning.

UVA (aging) rays penetrate deep into the dermis, the skin’s thickest layer, and are primarily responsible for premature skin aging, which can take the form of  wrinkles, dark/age spots, dryness, hyperpigmentation, loss of skin tone, loss of skin texture, loss of collagen and sagging. That said, shorter UVA rays can also cause sunburns. UVA accounts for up to 95% of the UV radiation reaching the earth. These rays maintain the same level of strength during daylight hours throughout the year. This means that during a lifetime, we are all exposed to a high level of UVA rays. UVA rays can penetrate windows and cloud cover. 

UVB (burning) rays penetrate and damage the outermost layers of your skin. Overexposure causes sunburns and, in severe cases, blistering. UVB intensity fluctuates. While the sun’s rays are strongest and pose the highest risk late-morning to mid-afternoon from spring to fall in temperate climates and even greater time spans in tropical climates, UVB rays can damage your skin year-round, especially at high altitudes or on reflective surfaces like snow or ice.

Do I need sun protection?

According to the CDC, skin cancer is the most common form of cancer in the United States with the American Academy of Dermatology Association estimating that 1 in 5 Americans will develop skin cancer in their lifetime. That means that roughly 9,500 Americans of all skin colors and ethnicities are diagnosed with skin cancer every day. Despite that, exposure to UV light is one of the most preventable risk factors for all skin cancers. 

Outside of the risks of skin cancer, daily sun exposure causes many other types of damage, including premature aging. The skin is the body’s largest organ, making up 15% of your total body weight. According to dermatologists, roughly 90% of premature aging is caused by sun exposure, a figure that only increases in people who use topical skincare products like acids or retinoids or get skin treatments like chemical peels or laser facials. 

Sun damage is cumulative and never completely heals. By protecting yourself from the sun’s UV radiation, you’ll minimize the dangers of skin cancer and will slow any premature aging. 

I have darker skin. Do I still need UPF/SPF?

Yes, everyone should take care to protect themselves. While more melanated or pigmented skin has more natural protection from the sun, those with darker skin are still at risk of skin cancer and other sun-related skin damage. It is true that skin cancer is more prevalent among those with lighter skin tones, however, those with darker skin tones who do develop skin cancer face higher mortality rates. 

I only need to worry about the sun’s rays during the summer, right?

Wrong. While UVB rays change their intensity based on the sun’s position and the seasons, deeply penetrating UVA rays are present with equal intensity during all daylight hours throughout the year. Even if you are not going outside frequently, UVA rays can penetrate clouds and reach you through car windows. Each day of the year, UVA rays can cause premature signs of aging including wrinkles, dark spots, loss of tone or texture, and collagen loss.


The information available on this website, including but not limited to information regarding UVA and UVB Rays and UPF, is general in nature; it is not intended as medical advice or a substitute for obtaining medical advice. Claudent makes no representation and assumes no responsibility for the accuracy of information contained on, or available through, this website, or its suitability for any purpose, and such information is subject to change without notice. This website, all of the information it contains, and all Claudent products are provided "as is" without any express or implied warranty. All implied warranties, including, without limitation, implied warranties of merchantability, fitness for a particular purpose, and non-infringement, are hereby expressly disclaimed. You are encouraged to confirm any information obtained from or through this website with other sources, and review all information regarding sun protection with your physician. Never disregard professional medical advice or delay seeking medical treatment because of something you have read on, or accessed through, this website.