Those "Tan Through" Shorst/Shirts: Do They Work?

[ralph124c]

I remember seeing adds for swimsuists, shirts, etc., made of a fabric that allows UV through. The idea is that the fabric lets through enough UV rays to allow your skin to tan, but not burn.
Has anyone tried these garments? Do they work as advertised, or is it another case of overadvertising?

[Vorpal_Blade]

@ralph124c

I remember seeing adds for swimsuists, shirts, etc., made of a fabric that allows UV through. The idea is that the fabric lets through enough UV rays to allow your skin to tan, but not burn.
Has anyone tried these garments? Do they work as advertised, or is it another case of overadvertising?

Probably have better luck in GQ.