You'll want to have a really high resolution texture to keep the tattoo from looking blurry at all. One way to clean up smaller images when you enlarge them -- a bit tedious, but it works -- trace the images using the pen tool, making paths. Then you can scale the paths (which are vector, not raster) without losing any resolution at all. One thing to keep in mind when adding ink to Poser figures -- some of the most common places for tats are the side of the arm and the side of the leg. These are also the hardest places to make them work in Poser, as most figures have the seam run right through the middle. There are a lot of seam guides online for all the characters, many even coloured. This will make it easier, but it's no piece of cake. It will probably take a few tries before you get tose sides to match up and look right, especially as you have to distort them some to keep them from being distorted.