The front/back gap is almost certainly because your pattern/painting whatever isn't extending far enough edgewise. The edges of the torso are where the front and back meet. Of course you know that to do shorts, etc., you need a transparency map in addition to a texture map. The trans maps should be easy to do in PhotoShop. You mention not getting a full fill--it would be extremely hard to fill the lined template. I use the magic wand to select the white empty area and then just invert the selection and fill with a solid color. Perhaps if you post a more specific look at what you want to do we could give more suggestions. I can see where Illustrator might be useful for some things but it sounds almost like you're using it to do some things that should be pretty easily done in PhotoShop--it may just take learning a few new techniques.

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