Just to further clarify: GH has 6 basic varieties of twists--brown and black twists presented in three sizes each. They all use the same leaf, African and Indian grown Virginia:
All our twist tobacco varieties are manufactured by the same spinning process using dark fired wrapper leaves. The filler is again, predominantly dark fired leaf with the addition of a small percentage of dark air cured Indian leaf.
There are three diameters of ropes: pigtail, bogie, and Irish. Pigtail is the thinnest, Irish, the thickest, and bogie is between.
These three diameters are then subjected to two different processes. The brown ropes are merely left as is, but some of these ropes are cooked, resulting in the black variety.
Lastly, there are some other aromatic variations (mostly with the brown ropes) where flavoring (rum, maple, and coconut being the most common) are added on top of the rope.
As the thread I linked to demonstrated, the descriptions on various websites are quite confusing because they reference everything from Kentucky to Burley to Virginia to Cavendish! But if we go back to G,H & Co's own descriptions, we can clear things up.