UV protection fabric

UV protection properties often make use of a transparent layer of UV-absorbent materials on the surface of the fabric. In other words, UV absorbers are organic or inorganic materials with strong absorption in the UV range of 290–360 nm, applied on textile fabrics to improve UV protection factor (UPF) and sun protection factor (SPF). Among them, nanostructures and natural materials are more active and effective because of their small size and more safety, respectively. 

Ultraviolet Protection Factor:
UPF 15, 20                    → good
UPF 25, 30, 35             → very good
UPF 40, 45, 50, 50+    → excellent