UV-Protective Factor or UPF
The Ultraviolet Protective Factor (UPF) rating system measures the UV protection provided by the fabric. UPF is very similar to the SPF Rating System used on sunscreen. A sun protective garment that is rated UPF 50 only allows 1/50th of the UV-radiation falling on the surface of a garment to pass through. Uvida Sportswear rated UPF 50 blocks 98% or 49/50ths of the UV-radiation that hits the surface of the shirt.
An independent testing laboratory tested Uvida Sportswear. The testing was done in accordance with the specific testing standards of the American Association of Textile Chemists and Colorists (AATCC) Test Method 183.