CasingClick for a glossary definition, a liquid that contained humectantClick for a glossary definition and flavoring concentrateClick for a glossary definition, was added to the tobacco. Here, on the New Cigarette FactoryClick for a map of L&M's Durham complex’s sixth floor, Mack Smith mixes flavoring concentrate that was prepared in the Research and Development Building’s kitchen. The concentrate contained many ingredients, including extracts of rum, prunes, sandalwood oil, and chocolate. Different flavoring mixtures were used in different cigarette brands, and recipes for the top-secret formulas were zealously guarded.