Sun Protective Fabrics Guide The level of sun protection provided by a fabric is affected by several factors, with the most important being the weave, followed by color, weight, stretch, and wetness. A denser or less open weave, as well as a heavier and less stretchy fabric, provide better protection. However, getting a fabric wet can significantly reduce its protection, except in the case of silk and viscose which become more protective when wet. Polyester, which contains a UV-absorbing benzene ring, and fabrics that have UV absorbers added during manufacturing, also offer higher protection levels. UPF (Ultraviolet Protection Factor) is a relatively recent rating system for sun protective textiles and clothing. It measures the ratio of UV that causes sunburn, which is blocked by the fabric. For example, a fabric with a UPF rating of 30 blocks 96.7% of UV, allowing only 1 unit of UV to pass through for every 30 units that fall on the fabric. This is in contrast to the traditional SPF (Sun Protection Factor) measurement, which is based on human sunburn testing. UPF measurements are made using a laboratory instrument. Standard for Sun Protective Clothing and Swimwear: UPF rating: UPF 15-24, UPF 25-39, UPF 40-50+ Protection category: Good, Very good, Excellent % UV radiation blocked: 93.3-95.9, 96.0-97.4, 97.5-98+ Fabrics Specifications HydroMaxx: HydroMaxx is a Bluesign certified, performance 2.5 waterproof / breathable membrane designed to keep water out while allowing moisture vapours to pass through. Water resistance is measured by the amount of water, in mm, which can be suspended above the fabric before water seeps through. HydroMaxx has been tested to withstand 10,000 mm of water resistance and 10,000 g/m2/d. Helishade: Helishade is a sun protective 100% recycled polyester, Bluesign certified fabric, and provides a sun protection rating of UPF 50+. The fabric also provides moisture-wicking properties and elasticity ensuring superior comfort and fit. Organic Cotton: Gots certified, grown without the use of synthetic agricultural chemicals, organic cotton is just as beneficial for you as it is for the environment. Chemical free cotton is hypoallergic and helps reduce absorption of toxins through the skin, thus reducing health risks. Coolmax: Moisture management is one of the key performance criteria in today's apparel industry. Coolmax stands out with its ability to transport moisture away from the skin to the outer surface. It also provides comfort stretch, good color fastness and a high UV protection, while being extremely lightweight. Jade: Unlike traditional cooling fabrics, ThermoCool is made from Jade stone powder, able to cool down the surface temperature by about 1-2 degree Celsius. CTR has incorporated ThermoCool into its collection to give you a more cool, dry, protective product. Since jade stone has positive electrons and is bacteria negative, it is virtually impossible for bacteria to grow on the fabric. Features: Structured Cotton Sombrero UPF50+ certified organic cotton Moisture-wicking sweatband Floatable brim Ventilated mesh crown Interior pocket Adjustable and removable chin cord 7 cm brim CTR by Chaos Altitude Ventilator Hat