There is a great variety of hand sewing methods in leather goods. Doeskin gloves are sewn with one needle and no pre-piercing of the holes for the needle to pass through. This so called running stitch makes a very flexible, but loose seam and works only for very soft leathers. Due to the higher density and thickness of leathers used for shoe uppers or bags, piercing the leather with a pricker before stitching is necessary.
Two needles are fixed on each end of the twine and pushed through the pre-punched hole from both sides of the piece to be sewn; one needle from the inside and one from the outside. When both needles have passed the hole, the thread is pulled tight on both sides. By applying unequal tension on the inside and outside thread and by intertwining or knotting the thread while pulling tight, the flexibility and elasticity of the seam can be controlled. As an example for such reinforcement by intertwining, inspect the inside of the seam of the tongue. Basically this is a simple running stitch (like the doeskin gloves) but on the part of the lining an additional thread is braided into each stitch for evenly distributed pressure on the lining material.
Our characteristic two-tone stitch used on the other parts of the shoe upper is a bit more complicated, since it is also made with two different types and coloured threads. It takes several hours and a lot of skills to make a pair. Nevertheless, besides the fact that a hand stitch is repairable, there are little practical reasons to justify such disproportional efforts. That is why hand-sewn uppers (with the exception of tubular moccasins) will hardly be found outside of purely single pair bespoke shoemaking. Our reasons are emotional and as it is in their nature they remain a bit vague. Clearly it makes us proud to develop and reintroduce aspects of true handcraft in serial production. And it definitely gives an aesthetic TWIST* to our shoes.
*TWIST is the name of our registered design of this specific stitch we use for uppers and belts. We do it always as a two-tone contrast seam.