35cm Birkin is pretty much a standard size for a calf leather Hermes birkin. When it comes to Ostrich Birkins the 35 size is almost an impossible dream. The house of Hermes likes to use the skin of one animal (in this case an Ostrich) when making a bag. This is so the skin will be of the same quality and grain on all parts of the bag. The Ostrich is a large bird, but does not produce great quantities of leather, so it's hard to get enough skin to make a larger sized bag. Most ostrich Birkins are the 30cm or 25cm size. Pictured is a Violine 35cm Ostrich Birkin with Palladium. A prestigious bag in a royal color and rare size!