It's also worth noting that even the best shoemakers use shoulder and belly...depends on the tannage and the application.
Once upon a time every part of the shoe was made of vegetable tanned leather (chrome tannages had not yet been invented). Some shoes are still predominantly veg. Heel lifts, stiffeners, welts and insoles are typically made from the margins of a hide. Insoles in particular want to be taken from looser and longer fibered areas--most often the shoulder.
I also take issue with the idea of vein shadows being deemed poor leather. Especially on outsole leathers, vein shadows tend to be most prevalent in areas where the best of the best leather is to be found--I & J in the illustration. I suspect the presence of vein shadows is more indicative of improper or insufficient shaving of the corium than weakness or flaws. And, except in extreme cases, I've yet to see a vein shadow that was hollow to any significant extent...not to where it would show up on the grain surface or affect the strength of the leather.
And it's worth noting that the layout of shoe components typically depicted (cutting for least wastage) may indeed be applicable to manufacturers of RTW (ready-to-wear) footwear (I have no doubt), but such illustrations are misleading in the extreme. No bespoke maker worth his salt would cut a hide in that fashion. Even two pair of shoes from a calf skin is pushing it, much less three pair. Esp. if it's really calf and not just cow labeled calf.
I think it was Thornton who said that prime calf skins...as used in the best of the English Trade...run around 6 square feet in size. Personally, I haven't seen many that small although kangaroo comes close. These hides nevertheless retain the belly and cheeks and shoulder when they are laid out on the cutting table. There's not a lot of prime leather in them if you're going to avoid those areas. Sometimes you're lucky to get one shoe out of each hide.
Small and perhaps trivial points but cautionary for all of that. We need to be careful when citing books or sources that are written for the manufacturing sector of the Trade. They are often penned/ghost written by people with little or no hands-on, practical experience and full of misinformation and expediencies.
This opnion was first voiced in our Leather Quality and Properties Thread
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