UPF is a rating system to measure the amount of Ultraviolet rays blocked.

tasc UPF is provided mainly by the bamboo fiber content. Bamboo fibers are light reflective (UPF protection) and reduce the heat radiation (temperature regulating). This is inherent in the fibers and not due to a chemical treatment or additive . It will last for the life of the garment and not degrade or wash/wear off over time.

Yes - keeping in mind that if the UPF is due to chemical treatments, it will degrade over the life of the garment.

Regular cotton fibers provide negligible UPF protection (around 5 dry and 3 wet).

Of course, tasc!

Bamboo! The natural UPF of a garment does come down to fibers used, thickness of fabric and knit/weave structure (more dense would have more protection) and for some fibers, the color (darker colors would provide more natural UPF than lighter)