Thanks Paloth, I wasn't thinking about procedural texturing. Yes, that would be the way to go. The distortion is also noticable on the skin of bent knees and shoulders, but less so, unless there are freckles.

I guess you could design a texture for a shirt with the pattern "compressed" in the breast region, so that it look right when stretched. It's already probably been done by someone. Would the texture map on dynamic clothing distort?- I'll have to do some playing around.