The worst for me is on lightweight, light colored flannel.  Under the collar you end up with the collar canvas, another piece of canvas, a piece of fluffy light flannel inlay and the flannel for the body of the suit.  That is the only time that it really bugs me.  Perhaps I am not enough of a cogniscento to enjoy it.  .

Cool Marc.  Thanks for the responses.  Perfection being unattainable and all, I will just have to live with a beautifully fitting jacket with one nick that bugs sometimes.  I think I can do that.

Interesting topic.

In the case of my jackets, even though I can easily feel the inlays by running the shoulder and back seams between my fingers (along the back seam the inlays measure 2 cm on each side) I can't get to see the inlays no matter how hard I try to spot them. But, none of my jackets is made of cloth below 10 oz. and I don't have yet any cotton jackets. The inlays are more likely to show through cotton, speaking from my experience with lightweight cotton trousers.

I think it comes down to how the tailor finishes the inlay edges. Some tailors like to leave the selvedge along the back seam. I would assume the selvedge is more likely to show through than a properly finished self fabric edge. With trousers, some makers do a turn-back along the inlays of the "ass seam" --not my preference as it tends to emphasize the inlays and can become slightly uncomfortable in critical areas. 

I will do some research on this topic and will write any findings here!