Fabric Feature: What is UPF 50+ and Why is it Important?

Have you ever known that something *is* important, but you’re not exactly sure *why* it’s important? Take UPF 50+, for example. It’s something that many people look out for when shopping for styles like swimwear or activewear, but what does it actually mean? 

We wanted to know a little bit more about what UPF 50+ is, and why it’s important, so we interviewed Ryan Lau, Primary’s Corporate Social Responsibility and Product Safety expert. Ryan works to make sure our fabrics are super soft, high-quality, sustainable, and most importantly — safe for kids to wear. 

What is UPF 50+? Why is it important?

Ryan: UPF 50+ is a measure of how protective an item of clothing is when it comes to absorbing harmful UV rays. For something to be UPF 50+, it means it absorbs at least 97.5% of the sun’s harmful rays that cause sunburn. It’s important because it creates more consistent protection for kids and baby when they’re in the sun for long periods of time, and doesn’t wear off like sunscreen does. Many of our styles – like kids and baby swim and our gender-neutral kids activewear – are made with UPF 50+ protection, so you can rest assured that the clothes your child wears on long days in the sun are comfortable AND protective. 

Shop these looks: the kids long sleeve rash guard in rainbow, the kids swim trunk, the kids short sleeve rash guard, and the kids swim trunk in gingham

That’s so cool! So wearing something that’s UPF 50+ isn’t the same as wearing sunscreen?

Ryan: No, sunscreen is measured in SPF, and that’s actually really different. SPF measures how long, depending on skin tone, sunburn can be prevented. UPF 50+ measures the percentage of ultraviolet rays that are absorbed by fabric. It’s sort of like SPF is a measure of time, and there’s no time limit on UPF – it always absorbs the same amount of sun. Both are important, but UPF 50+ clothing offers more consistent coverage, so you don’t have to worry about constantly reapplying sunscreen. Our UPF 50+ rash guards for kids and baby offer different levels of coverage with this in mind, and you can be sure kid won't get streaky, patchy tan lines. In fact, we recommend our UPF 50+ styles for anytime kids spend in the sun – especially baby, to help protect sensitive skin

Shop the look: the baby sun hat, the baby long sleeve rash guard, and the baby swim diaper.

How does it…work?

Ryan: Two things make our activewear and swim styles UPF 50+: the way the fabric is made, and what the fabric is made of. 

• What it’s made of: Our UPF 50+ styles are made with special, synthetic fibers that are superheroes when it comes to absorbing the sun’s rays – think of these as strong building blocks that create a super-safe boundary between your skin and the sun.
• How it’s made: Those special, synthetic yarns are knit together with a really high density, which means that we put a large amount of fibers really close to each other, making it much harder for the sun to penetrate the fabric. For some context, our soft cotton jersey fabric is made of about 1800 knits per square inch. Our StayCool UPF 50+ fabric has 8000 knits per square inch. 

Wow! What makes those special fibers so good at absorbing UV rays?

Ryan: The material in our swim and activewear styles is recycled nylon & polyester that has been repurposed from pre-and-post-consumer waste. Sometimes, it’s as simple as taking pieces of unused or wasted fabrics from our manufacturing partners. Other times, it means taking harmful plastics like fishing nets out of the ocean and repurposing them. 

These materials are manufactured to be stronger, and more dense than typical everyday fabrics. Since plastic is engineered to be a lot less breathable than something like cotton, it makes a better barrier for your skin once it’s been recycled into our soft, stretchy fabrics.

So UPF 50+ styles from Primary are protective and better for the environment?

Ryan: Yes! And we’re working on making even more of our styles sustainable. It takes a long time to plan where the materials will come from, how we’ll repurpose them, and what purposes those materials will have. We’re proud that more than 100 Primary styles use recycled materials, and we’re excited to increase that number in the future.

Amazing! So, would you say that the UPF 50 protection puts the “Cool” in our StayCool styles?

Ryan: Partially! But there’s some other fabric technology there. We created our StayCool styles to be moisture-wicking, to help kids cool down faster while they work up a sweat.

Shop the look: kids StayCool sleeveless top, the kids StayCool racerback tank, the kids StayCool running short, and the kids StayCool gym short

How does a shirt wick moisture? Is there a special class it needs to take?

Ryan: Ha, no class required! It’s a special treatment we give to our clothes. The finishing on our StayCool styles helps the fabric absorb moisture, and then disperse it across the entire garment. Having the moisture evenly dispersed means it will evaporate much faster, making something like this kids StayCool pullover hoodie, or the new rainbow StayCool kids racerback tank dry much quicker than a regular shirt!

Wow, so much science in such tiny clothes. Is there anything else that’s special about these styles?

Ryan: Just that during all these processes to make clothes safe and practical for kids, we take extra time to make them super soft and gender-neutral. It’s important to everyone at Primary that kids feel comfortable in clothes, in every way. 

Shop the look: the kids reversible swim hat, the kids long sleeve rash guard in rugby stripe, the kids swim trunk in polka dot.

Thanks so much, Ryan! Shop summer-ready styles with UPF 50 protection now, including performance active styles for kids, and gender-neutral swim for kids and baby. 

Share your family's summer looks on social by tagging us @primarydotcom with #yesprimary.