Tattooing involves the placement of pigment into the skin's dermis, the layer of dermal tissue underlying the epidermis. After initial injection, pigment is dispersed throughout a homogenized damaged layer down through the epidermis and upper dermis, in both of which the presence of foreign material activates the immune system's phagocytes to engulf the pigment particles.
Actress Katie Cassidy (Arrow", "Gossip Girl", "Melrose Place") has a few tats. The tattoo on her foot of three stars depicts Katie and her two sisters Jaime and Jenna, who also each have the same tattoo. Katie also has a tattoo word-ring going around her left ankle, which reads Love Thyself, Know Thyself, Be Thyself.