- SINGLE LAYER PREMIER LEATHER WITH ARCH SUPPORT AND A HALF INCH NARROW STRAP. NAVY. The single layer premier leather sandal is made of top grade nubuck leather; the top sole is embossed with the Rainbow logo. This model comes with a half inch narrow strap, also nubuck leather; it is double stitched, and the nylon toe piece is secured with a box X stitch, all using bonded nylon thread. The single layer mid sole and arch support is triple glued for maximum durability to our non-slip Rainbow bottom. We finish it off with the Original Rainbow woven label on the right strap, the mark of a genuine Rainbow Sandal.