This special fondo America method consists of sewing the upper, insole and outsole together inside out, leaving a small opening at the tip for inserting the wedge (at the heel) and the felt (in the front). Only then is the opening sewn shut and the whole is prepared to be shaped. This fondo America or a sacchetto technique is the strong point of the shoe and is what makes it so very comfortable and stylish. The entire process requires a great deal of shoemaking experience and can only be done by experts who are well-trained in the art of handcrafting footwear. Not only, but it is typically used to produce slippers and makes them incredibly soft, flexible and lightweight. In short, a Farfalla slipper is expertise and craftsmanship of the finest quality.