The bottom is smooth, not ribbed. Please see my other auctions for additional vintage Le Creuset pieces, antique copper cookware, mid-century modern cookware, Dana Buchman and Ralph Lauren clothing, vintage Coach handbags and vintage southwest jewelry. The item "Vintage Le Creuset Enameled Cast Iron Doufeu Flame Excellent" is in sale since Sunday, December 06, 2015.This item is in the category "Collectibles\Kitchen & Home\Kitchenware\Cookware\Cast Iron". The seller is "rockymountainjan" and is located in Phoenix, Arizona. This item can be shipped to United States.