Shoe vamp means that the vamp behind the shoe is soft, which can be used as slippers and cloth shoes. "Thread the midsole" is a way to observe the thread after pulling down the upper.

The middle bottom line refers to the line under the insole of a shoe. Midsole is an important part of shoe recognition. Midsole wiring, each stitch and each thread basically keep the same spacing, and the outermost side of the wiring is in a perfect U-shape. The density of false threads is different, and both the direction and the outermost stitches are messy and rough.