It’s not hard to apply a tattoo to skin texture prior to rendering, but depending on where you apply it, your design might stretch/distort when you pose the character. Plus, it’s a real chore to place your tattoo across seams, like for instance, on midback. This is a short (three-minute) tut I put together showing my method (after MUCH trial and error) for adding a black and white tattoo to a DAZ 3D character in post work (Photoshop Elements). I particularly wanted to find a way to preserve the skin’s texture, while also keeping the shading/highlights of the character’s body shape (musculature). It’s not rocket science, but it might help.