Please check your designers; this is not a Chanel gown. Christophe Josse is an Official Member of the Chambre Syndicale de la Haute Couture in Paris. This exquisite gown is from his Haute Couture S/S 2012 Collection.
Black muslin dress, (Translated) Black wool muslin gown, with flared sleeves, tight fitting bodice and five strips (tiers) on the skirt. The bodice with V-neck runs from the front into a point and is lined.