Recently I made a Whole plate Band case (see images below) to reproduce a vintage one that sold on ebay. The Band case style was a patent of Henry Eichmeyer from Philadelphia c1855. In became a much mimicked style, the raised bands serve two purposes;
1. The case can be left under a weighted board while the glue that adheres the leather dries. Normally a pressing frame is used that only puts weight on the edges of the case (so the leather grain is not crushed and flattened under the weight) and so you need different ones for each format size of case.
2.The raised bands keep the furniture (clasps) from sitting up on the surface of the case, scratching other surfaces like table tops, other cases etc. I hand make these clasps as it is just not possible to buy ones that look right.
The Eichmeyer design uses a single leather covering, which is tricky, especially in the whole plate size. Its is much easier to have separate spines from face leathers. The desgin also has rounded edges on the long rails and the cover boards are both domed as with a Boston case.