Soles of Silk IS NOT an adult Web site. It is a hobby site showing artistic and casual images and video of female feet in everyday settings and/or situations. Nowhere in the site are there depictions of nudity or sexually explicit conduct as described by U.S. Code Title 18, Part I, Chapter 110 that describes sexually explicit conduct, actual or simulated as: "sexual intercourse, including genital-genital, oral-genital, anal-genital, or oral-anal, whether between persons of the same or opposite sex; bestiality; masturbation; sadistic or masochistic abuse; or lascivious exhibition of the genitals or pubic area of any person."
Although not an adult site, Soles of Silk does contain a membership area in which adults with valid credit cards or with other accepted forms of payment can view more images/video. The membership section also DOES NOT contain any depictions like those mentioned above. If you're looking for that, you should try elsewhere. All models, nonetheless, were age 18 or older at the time of photography.