If you can find the "advanced shaders" from shaderworks (used to be free at RDNA, do not know where to find now) and are willing to learn, it is possible to create tattoos that can be applied to any texture for a given character. I wont say it is intuitive, but it can be done http://www.sharecg.com/v/74873/view/11/Poser/M4-Back-Tattoo

Bill

People that know everything by definition can not learn anything