Goodyear Welt is the oldest, most elaborate and most durable method. It can be done by machine or by hand. The first part of the process is to prepare the template for sewing.
A spring is created perpendicular through the template. The second step is to put the mezzanine that normally molds to the sole and both are joined. In the last step the sewing is carried out. This is when you sew the top with the insole and the midsole. Through another stitched welt is attached to the sole.
For this sewing is used a Lockstitch, so if at any point of the sewing there was a break, the chain would not be undone. The great advantage of this sewing process is that if the sole decomposes, the replacement of the same is very simple and can be done both machine and hand. The extra layers make the footwear more waterproof and durable.