UV protection in fabrics: Your complete guide

UV protection in fabrics is an excellent way of protecting your skin from the sun. Many garments are made from materials that naturally absorb a large proportion of the sun's rays. They don't absorb them all, but offer great protection against sunburn, cancer risks and other problems that sun exposure can cause.
This article is a comprehensive guide to the UV protection of Wazoodle fabrics. Among other things, we explain how UV tests are carried out, how to find out the level of protection, and how light and dark colors differ in the protection they offer.

The difference between UPF and UV ratings

To begin with, it's essential to understand the difference between UPF (Ultraviolet Protection Factor) and UV (Ultraviolet) ratings.
The UPF rating indicates how much of the sun's ultraviolet rays are absorbed by the fabric and not by your skin. A higher UPF rating offers better protection, but a lower rating is better than nothing.
If you buy a fabric with a UPF 20 rating, only 1/20th of the UV rays will pass through the fabric. 20 times less radiation will reach the part of your body covered by the fabric.

How the UV test works ?

Another important aspect of UV protection in fabrics is understanding how UV testing works. There are a number of preconceived ideas about testing that it's important to review.
Firstly, UV tests are carried out on a single layer of fabric, which means that multi-layer materials will have even better UPF ratings. But while you might think that all you have to do is add up the UPF ratings, the calculations are more complicated.

Let's take an example.

A piece of fabric with a UPF rating of 15 means that around 93% of UV rays are blocked. Around 7% of these rays can reach your skin. 
Now imagine that your second piece of fabric also has a UPF rating of 15. You'd think the combined materials would have a UPF rating of 30, wouldn't you? But no, that's not how it works. The UPF rating would be 50+ because of the second layer of fabric. This second layer blocks 93% of the 7% of UV rays that the first fabric layer lets through. This means that only 7% of that 7% will actually reach your skin. That's a lot of protection!
If you're a mathematician, the calculation is 100 - (0.07*0.07) = 99.9951%.
There are three UPF index categories: good, very good and excellent.
Good: 10 to 24
Very good: 25 to 39
Excellent: 40 to 50
Protection is more than excellent if you see a piece of fabric with an index 50+. Less than 2% of the sun's UV rays reach your skin. You won't find better!
But even a low index, 10 for example, offers significant protection against ultraviolet rays.

How different colors absorb the sun's rays

Different colors absorb the sun's rays in different ways. Darker colors absorb UV rays rather than letting them pass through the fabric to your skin. If you're out hiking all day, a black or red shirt will protect you better than a white one. 
Light colors still absorb the sun's rays, but not to the same extent, and so don't offer the same level of protection as dark colors.
Colored fabrics offer better UV protection due to the benzene atoms contained in the dye molecules. These atoms absorb ultraviolet rays. Thus, wearing a light-colored dyed shirt offers better protection than a light-colored shirt that has not been dyed.

The influence of fabric structure on UPF rating

There's no guarantee that two black shirts will necessarily have the same UPF rating. In fact, fabric structure affects the amount of UV rays blocked.
Unbleached cotton contains natural lignins that act as UV absorbers. A single-knit fabric has a lower UPF rating than a double-knit fabric. A flat knit fabric has a lower UPF rating than a raised fiber structure.
Take fleece or French Terry, for example. Because they are double knits and the fibers are intertwined, it's very difficult for light to pass through, and they offer excellent UV protection.
Wool is another good example. It can block both UVA and UVB rays, while some fabrics can only block UVA or UVB rays, but not both. Tightly woven or knitted fabrics offer better protection than loose fabrics. So you could have one black shirt with UPF 15 and another with UPF 30.

What's the difference between UPF and SPF?

SPF (sun protection factor) indicates the time it would take for the sun's UV rays to redden your skin if you use the product exactly as indicated, compared to the time without sunscreen. The term SPF is not used for clothing, but rather for skin applications such as sunscreens, creams or lotions when your skin is exposed to the sun's rays.
UPF measures the degree of protection a fabric offers your skin against UV rays, and the amount of UV rays it absorbs so they can't affect your skin. 
For example, a UPF 50 fabric blocks 98% of the sun's UV rays and lets in only 2% (1/50th), considerably reducing your risk of exposure. On the other hand, if you use an SPF 50 product on sun-exposed skin, it will take 50 times longer to burn than if you don't wear any cream.

UV protection in Wazoodle fabrics

Wazoodle Fabrics actively strives to provide its customers with more information about UPF ratings. We test all our fabrics for their UPF rating, and add it to the "Specifications" tab on all our product pages. 
To check a fabric's UPF rating, go to the Specs tab to see if we've already tested it. You can also look for the UPF icon on the product page that indicates the fabric index. 
If you see two icons displayed - one for UPF 10 and UPF 20 - the fabric has a UPF index range from 10 to 20. The index is 10 for light colors and 20 for darker colors. 
Wazoodle Fabrics offers many fabrics with the best combination of fiber, construction and color to provide the best UV protection. 
The Zorb® range offers the best protection. The interlocking structure of Zorb® super-absorbent fibers blocks most UV rays. In fact, it was the interlocking structure of these textiles that made them ideal for germ-blocking masks at the height of the coronavirus pandemic.
The ProECO® and ProCOOL® ranges also offer good to excellent protection. ProCOOL® polyester fabrics contain an ester (benzene) ring that absorbs UV light, allowing the fabric to last a long time without degrading or exposing you to the sun's rays.
During the dyeing process of our polyester fabrics, the material is colored by heating the solid dye to steam, opening the pores and allowing the pigments to penetrate. This exponentially increases UV protection. 

Try Wazoodle fabrics

Looking for UV protection in fabrics? Even without a current UPF rating, many Wazoodle fabrics offer excellent UV protection. Look for dyed fabrics with a tight knit/weave for the best protection.
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