well, there will be three layers at least; the uv template, a black layer, and a white layer. Anything painted black will be transparent, anything white will be opaque, with grayscales in between creating different opacities. The easiest way to build a transmap is to open the uv template in photoshop, save the file as a .psd Then fill a new layer with white. Then create another layer, and hide the white layer. On this third layer, you can paint black. After you've painted a portion, show the white layer and save the .psd file. Apply the WIP trans map as a texture on the figure in poser. Looking in the preview window, you will have a reference for the work you're doing inside photoshop. As you work on the trans map, save it and then render in poser. You can track your progress this way and eventually you will have the results you're hoping for.Theres more to it to this, but this gives you a basic idea of the process involved.