"The construction techniques ... practiced today, with minor variations, by the finest tailors all over the world, have changed very little in the past 100 years. Although new machines and new methods of fusing layers of fabric together offer today's tailor speedy alternatives to time consuming handwork, relatively few of these faster methods have been adopted by custom tailors. The sewing machine is used for almost all seams and darts, but almost 75% of all stitches in a custom-tailored suit are still done by hand, to ensure the most accurate shaping of the fabric. The new fusible interfacings are being used to reinforce certain small areas, such as dart tips or the inside of some pockets, however, they are not considered acceptable substitutes for the multi-layered, hand-stitched canvas interfacing which gives body to the entire front of the jacket."
-Classic Tailoring Techniques, by Roberto Cabrera and Patricia Flaherty Meyers
The photo, from Cobbler's Laboratory, is of a detail from a bespoke Fallan & Harvey tweed suit.