The Science of UPF 50+ Clothing and Sun Hats: Why Fabric Rating Matters

If you’ve ever slipped on a long sleeve tee and still ended the day pink, you already know that not all fabric protects you from the sun. At Solbari, we design UPF 50+ clothing that does more than cover skin. We engineer textiles tested to UPF 50+, the gold standard for sun protection. Here’s the science behind that rating and why it should guide every warm weather wardrobe decision. 

UPF vs SPF: UPF is for Fabrics and SPF is for Sunscreen
UPF (Ultraviolet Protection Factor) measures how much UV radiation, both UVA and UVB, penetrates fabric and reaches your skin. A UPF 50+ garment blocks at least 98% of UV rays, so only up to 2% of UV rays get through. SPF is for sunscreen on skin and primarily reflects UVB protection. Think of UPF as wearable shade because the protection is built into the fabric and doesn’t rinse or sweat off. You can learn more about UPF ratings on our 'UPF 50+ Explained' information page.

What really changes fabric protection 

Fibre type. Synthetic fibres like polyester and nylon scatter UV more effectively than many natural fibres. High-quality cotton, bamboo, and modal can still achieve UPF 50+ when engineered correctly using breathable UPF fabrics. 

Yarn density and construction. Tight, compact knits and weaves create fewer windows for UV to pass through. Airy, open structures can allow significant UV transmission. 

Colour and dye chemistry. Darker, more saturated colours often absorb more UV. Purpose-selected dyes can further enhance blocking without making garments heavy or hot. Explore this in our UPF 50+ Active Fabric range.

Finishes and additives. Some textiles use UV-absorbing treatments. At Solbari, our focus is on inherent sun protection engineered into the yarns and structure so performance lasts. 

Moisture and stretch. Wet or overstretched fabrics can lose protection as gaps open. True UPF 50+ garments are tested in real-world scenarios, including when damp and under tension - just like our long sleeve UPF 50+ tops.

Wear and care. Abrasion and laundering can degrade ordinary fabrics. Purpose built UPF textiles are designed to maintain performance over the life of the garment. 

Why UPF 50+ is the sweet spot 
UPF ratings run from 15 to 50+. A UPF 30 fabric blocks about 96.7% of UV, while a UPF 50+ fabric blocks 98%+. The difference looks small on paper, but adds up over hours in intense sun. For sun-sensitive skin or anyone who spends long days outside, UPF 50+ outdoor clothing provides the extra margin your skin needs. 

Breathable, not bulky 
Modern UPF fabrics can be lightweight, breathable, moisture wicking, and cool to the touch. By optimising yarn cross sections, weave geometry, and airflow, Solbari achieves high protection without heat trapping bulk so you stay comfortable on peak UV days. Discover our cooling UPF 50+ fabrics.

Lab testing you can trust
Authentic UPF performance isn’t guesswork. Reputable brands test to recognised standards such as AS/NZS 4399, measuring UVA and UVB transmission across multiple wavelengths and conditions. All Solbari fabrics are tested UPF 50+ by accredited laboratories. 

Sun hats: the most powerful UPF 50+ upgrade
Clothing covers your body, and a UPF 50+ sun hat shields the areas that see the most daily exposure such as the face, ears, and neck. Solbari’s wide brim UPF 50+ sun hats offer 360 degree coverage that outperforms ordinary caps, significantly reducing incidental UV on the nose, cheeks, and scalp. For all-day adventures, our men's UPF 50+ sun hats and UPF 50+ legionnaire hats with a neck flap protects the back of the neck and ears, which are key zones for cumulative sun damage. 

Prefer something travel friendly? Our packable UPF 50+ sun hats fold flat, pop back into shape, and deliver shade you can rely on from beach to boardwalk. We design women’s and men’s UPF 50+ sun hats with adjustable fits, breathable panels, and lightweight sweatbands so you’ll actually keep them on.

Pair your hat with UV protective sunglasses and a high neck UPF 50+ top - like our long sleeve UPF 50+ tops, to create a shaded micro-environment around your face and décolletage. It is an elegant and effortless anti ageing routine you wear. 

How to choose UPF gear that works for you
Look for a clear UPF 50+ label rather than vague sun safe claims. Prioritise coverage with long sleeves, high necklines, thumbholes, and full-length leggings to expand protected surface area. Match fabric to activity with quick-dry, chlorine-resistant pieces for water - such as our UPF 50+ swimwear - and featherweight knits for everyday wear, like our lightweight everyday UPF 50+ layers. Choose a comfortable fit that moves with you without overstretching at the shoulders, elbows, or knees. Remember that clothing is your first line of defence, and use SPF on exposed areas, reapplying regularly. 

The Solbari difference
Our mission is simple yet powerful. Make sun protection effortless and beautiful. Every Solbari UPF 50+ piece —from buttery-soft everyday layers to performance swim and UPF 50+ sun hats —is engineered for all-day wearability with flat seams, breathable panels, cooling fibres, and a soft hand feel. 

Fabric rating matters because your skin’s health matters. When you choose UPF 50+, you’re choosing a proven shield against UV that works the moment you get dressed. Explore Solbari’s full UPF 50+ collection and step outside with confidence.