Ah, I see. No, replication of certain leaf isn't the purpose that casings serve. The purpose of casing is to subtly augment the chemistry of certain leaf to mitigate chemical effects like tongue bite or rough edges. Casings can't be used make a Red Virginia taste or look like Bright, or Orange Virginia taste like Red. But it can be used to reduce bite and offer natural nudges to the existing sweetness and flavor profile of the leaf to which it is applied. We don't have 20 grades of Virginia because we are a very small company with limited storage space and we do everything by hand, including our processing, which is enormously time consuming. We have the types of leaf that we need to produce the blends we like and want to make. If we want to make something new and we don't have the necessary leaf, we source it. Very often, there may only be a few thousand pounds of a particular grade or lot available, and if we were a big producer, with large machinery, a few thousand pounds would not go very far, thus requiring several different lots to be purchased, and blending those lots together to reach the desired nicotine and sugar averages for the leaf for the leaf in question. For us a few thousand pounds of any one type of tobacco can last for well more than a year or two, so amassing stockpiles to be blended together isn't necessary for most things.
We don't have any use for filler grades, and we don't blend using spreadsheets to determine rote chemistry averages of target nicotine and sugar, we source the leaf that has the sugar, nicotine and color that we want and because we don't produce a gazillion pounds of one or five or 15 products at a clip, we don't need 20 different grades of one style of leaf to spread across our blends in order to make our production and chemistry targets. Again, we have less than 20 blends that utilize casing and that includes Burley, Virginia, Oriental and Latakia blends as well as aromatics. We produce hundreds of different products in small batches, usually 56- 80 lbs. at a crack. Each of these blends are made to individual, unique recipes from one another, and are all made using the 20 or so tobaccos of different types that we use. The vast majority of these are uncased and many are not topped either. Adding a small amount of sugar or honey, or molasses won't replicate the flavor of a totally different leaf, it will only adjust the mouthfeel and to a far lesser extent, the flavor of the leaf in question.