About UPF Clothing

What is sun protective clothing?

The Federal Trade Commission regulates the labeling of sun protective clothing such that all clothing labeled as sun protective must also state the certified Ultraviolet Protection Factor (UPF). Similar to the SPF of sunscreens, clothing is labeled with the associated UPF.

The highest UPF rating possible is UPF 50+ and is classified as "excellent sun protection," blocking over 98% of UV rays. All SUMMERSKIN apparel is rated UPF 50+.

Clothes with less than a UPF 15 cannot be labeled as sun-protective.

A standard white cotton T-shirt typically has a UPF 5-7.

How is UPF determined?

The UPF of fabric is affected by the thickness of the fabric, the tightness of the weave, and the color. The darker the color the more inherent the sun protection. The trick is to balance the sun protective qualities with the comfort and style of the fabric.

Bamboo lends itself well to fabric blends for sun protective clothing as it is a delicate fiber that can be blended with other materials, such as cotton and spandex, to create a tightly woven fabric that is both light-weight and incredibly soft.

SUMMERSKIN products are independently tested and certified for their labeled UPF. We follow stringent industry guidelines and testing standards set by the American Society for Testing and Materials (ASTM), and the American Association of Textile Colorists and Chemists (AATCC). Unless otherwise stated, all SUMMERSKIN garments are labeled with the UPF that was determined by testing the fabric in a dry and unstretched state, as the UPF of the garment may be altered if the fabric is wet or stretched.