I might add that very few companies still cut channels in the insole as part of their GY operations (I only know of one and, AFAIK, they don't do all their shoes like that).
Additionally, while the full canvas "undersock" in the video has much to recommend it (even a certain perverse functional logic), it too has been abandoned in favour of just a strip of canvas. Almost entirely.
I can't believe that such a paltry difference in the cost of raw materials--the full undersock versus the folded strip--would force the shift away from the full undersock. But there it is.
It's hard to imagine any reason but cost cutting and expediency.
Edited by DWFII - 3/25/15 at 9:07am