Was pleasantly surprised with these shirts. Since I have severe sun sensitivity, I have to be careful with having shirts that you can see through when you look through the back of the shirt in the light. Not sure how much UPF shirts like that protect your skin. This one is tightly woven, the material appears stronger than many polyester shirts, and you barely see anything through it. However, the black shirt appeared less tightly woven than the other colors where you could see through it. There is only one other brand that I found to be like this on ebay so I will be sticking with these two brands.