MrD11InYa When I want something different than a pre-packaged DAZ asset, I usually go and try to find a transparent background PNG file. Then I use it as a L.I.E. (Layered Image Editor) layer on the particular surface I want the tattoo to appear on. For characters you would need to place the PNG in the same spot on both the Base Color image and the Transparency Color image and play around with the opacity of the layers since most tattoos are not made with very bright plastic looking inks. Graffiti on walls, images on clothing and the like do not usually need more than an added layer on the Base Color image.
All L.I.E. layers will conform to the shape of the model they are placed upon.