If you have ever smoked "raw tobacco" you would probably exit the hobby. Casings prepare raw tobacco to become palatable. Top Dressing is added for aromatic blends to achieve a flavor the blender desires. The article referred to above is excellent and should clarify the subject for everyone. An example is my Cornell and Diehl Blend named Captain Bob's Blend. It is a light English Style Blend and does contain some Latakia. It is an aromatic blend that contains Latakia. A Topping is applied. One ounce to the pound extremely concentrated. The topping is a mixture of six flavors. Those flavors consist of vanilla, orange, black walnut, caramel, maple and grape. Smoking CBB without the topping is also wonderful, but not an aromatic. The raw tobaccos are cased and very palatable. I prefer the light topping which makes it a light English aromatic.