The source artwork I use for tattoos is the "flash" artwork that real tattoo artists design and use as a templates for their work. Walk into most tattoo parlours and hanging on the wall or in their design books you'll see a huge selection of artwork you might want to have a tattoo of. So just Google Image Search with the keywords tattoo + flash and you'll find ample sources to use. Be sure to use an image that is public domain (or ask the author first). It's possible to cut and paste tattoos off the body or image of a person and use different blending methods to achieve a similar effect, but it is very time consuming and much more difficult to get good results. For Geri's arms, legs and torso I used just 3 pieces of flash artwork.