My main goal is to be able to take existing photos and age them by altering skin texture and wrinkles etc. What I want to do is create a "wrinkle" master file where I can take photos, basically isolate the wrinkles and use them for future images. How can I take an image, say a face with wrinkles and get just the wrinkles to use as layers for other images?
Well that is the opposite to the question we are usually asked
You might want to take a look at this "aging" tutorial by Jesus Ramirez who is also an ACP in this forum. It shows how to take wrinkles from one photograph and use them on another using the patch tool
Something using the High Pass filter, I'd say,