Sole adhesion is the process of securing a sole to a shoe upper. Cementing, sewing, or glueing are the three ways most frequently used to accomplish this. The most popular technique is cementing, which entails attaching the sole to the upper with an adhesive. A more conventional method is to stitch the sole to the upper using a sewing machine. The more recent technique of sole adhesion is employing an adhesive to join the sole to the upper.