Sportswear with UPF 50+ tested fabrics
What does UPF mean – and what is AS 4399?
UPF (Ultraviolet Protection Factor) measures how little of the sun's UV radiation a fabric allows to pass through. A fabric with UPF 50+ allows less than 1/50 of the UV radiation to pass through under the laboratory measurements prescribed by the standard.
AS 4399:2020 is an Australian standard that measures UV protection on dry, unstretched fabric under a simulated Australian solar spectrum.
The fabric is tested – not the product
Individual fabrics are tested according to AS 4399:2020 – not the finished product. A finished product consists of multiple components (seams, elastics, panels, design), and the level of coverage varies from product to product.
Why the fabric protects
The UV protection properties of the fabrics come from the construction itself – the yarn structure and a tight weave/knit with high surface coverage – not from a surface treatment. This means the protection does not wash out or decrease over time.
Titanium dioxide in the yarn gives the fabric high opacity and a bright, SuperWhite appearance, while also increasing how much light the fabric reflects. Yarn with a high filament count provides better surface coverage.
Does the clothing retain its UV protection after washing?
Yes. Because the UV properties come from the fabric's construction and not from a surface treatment, they do not decrease with regular washing or over time.