The Rainbow Willow Double Layer Arch Women’s Sandals. Its about time the Double Layers have some fun. and a cute strap design.This is The Willow sandal from Rainbow. This whimsical sandal is the first of the cute fashionable options available in a Double Layer. Up until now cute has only been the standard single layer. Using the traditional double layer foot bed we reversed the folded strap, and inset a cute three piece braid into the leather giving it a secure foundation but raised just enough to see the hand braided pattern.