Small Belt Chain Calfskin Quilted Leather Flap BagA Chanel Flap Bag in quilted calfskin leather. The Flap Bag has a storied history: it was first debuted by Gabrielle Coco Chanel in the '50s and then later re envisioned by Karl Lagerfeld in the '80s. The Flap Bag comes in many different styles. The most common materials are calfskin, lambskin and caviar, although it is available in more exotic leathers such as lizard and ostrich. The most common sizes are Mini, Small, Medium, Jumbo and Maxi.