construction where the upper is lasted without any insole beneath, an additional piece of lining is laid within the void on the bottom of the last, the edges of the upper and bottom lining are turned up to form lips that are sewn together, closing the “bag” of the upper, and the closed bag is then inside sewn or Blake stitched to the bottom
Bologna construction produces more flexible shoes than constructions with insoles. It’s especially popular for lightis slippers.