Wetlook World Forum

Sadly, physics textbooks do not provide an explanation of why wet white fabric is translucent, and I doubt anyone has published a scientific paper called “The optical properties of the wet T-Shirt compared to those of its dry counterpart”.

Having said that, someone has done some research into this subject because someone once said in a sunburn protection news story on TV, that “wet clothes provide no UV protection”; not strictly accurate, because dyed and heavier clothing does provide some sort of UV protection, which I read on a total coverage swimwear website.

Going back to the mechanism of what is happening; this is mainly guesswork, but what I think is happening is that when you see “transparent” white wet clothing, you are not looking straight through it, but instead the image you see is from light that has passed into the water on the clothes, becoming trapped to a degree by the water's refractive index, bounced off fibre surfaces onto other nearby fibre surfaces until it has escapes out of the other side when it is travelling nearly perpendicular to the water surface.  It then reflects off the wet body or undergarment surface below before making the return journey by the same manner.  You are therefore not looking at light that has travelled in a straight path, but light that has bounced about a lot.  On dry clothing, the light hits dry fibres that do not reflect, but just scatter a portion back giving the white surface you see.  Dark clothing does not go as translucent because the dyes in the fibres absorb much of the light.