Clothing is the very “first line” of defense against harmful ultraviolet rays from the sun that protects our bodies from blocking or absorbing this radiation. When outdoors on a camping trip the more you are able to cover your skin the better.
What Is UPF?
UPF is short for Ultraviolet Protection Factor and is an indication of the fraction of the UV rays is able to penetrate a fabric. For example, a shirt that has a UPF of 50 will allow only 1/50th of UV radiation from the sun to absorb into the skin.
Even when you wear clothing that covers every inch of the body, if the sun is able to get through, the clothing is not very useful. The fabrics are designed with many tiny fibers that are knitted or woven together. When looking through a microscope there are spaces between these fiber and this is where the UV rays can pass through the holes and reach your skin. The tighter weaves and knits mean smaller holes which mean less UV is able to pass through. The twill used in making denim or tweeds is examples of tightly woven fabrics.
When thinking about the clothes to wear for a camping trip keep in mind that synthetic fibers like acrylic, nylon, lycra and polyester are more protective options than lustrous or shiny semi-synthetic fabrics such as rayon or bleached cotton that reflect more of the UV rays than matte fabrics such as linen that absorb. Finally consider the density and weight of the fabric. Sheer and light silk gauze provides a lot less protection when compared to a cotton, heavier denim. Look out for the clothing items that have a minimum of UPF 30 and rather choose items of clothing that cover more of your skin.