Both red and white Bordeaux wines are almost invariably blended. The permissible grape varieties in red Bordeaux are: Cabernet Sauvignon, Merlot, Cabernet Franc, Malbec and Petit Verdot. While wine making styles vary, a rule of thumb is that the Left Bank is predominantly Cabernet Sauvignon based with the Right Bank being more Merlot based. The Graves area produces both red wine (from the grapes previously mentioned) and white wine from the Sauvignon blanc, Sémillon and Muscadelle grapes. The area of Sauternes (including Barsac) is known for its botrytized dessert wines.