Bradel Bindings originated in Germany and are another example of a case binding much like flat back notebooks I discussed before. The major difference between flat backs and bradel bindings is that the spines are rounded and backed which creates a stronger spine and reduces the likely hood of the book drooping under the effects of gravity. In essence the sections support one another like pillars once they are formed into a round.
Much of the process of making a bradel binding is very similar to binding a flat back notebook, sections are folded and pressed. Marked up and sewn before the end papers are attached. From here the process is a bit different, firstly the spine is given a light coating of PVA before the spine is worked in to a round with a backing hammer, it could be left at that but a lot of modern bindings take it a step further by doing a process known as backing. Backing a text block involves putting the text block between special boards in a press and using a hammer to evenly work the spine over to form a distinct lip for the cover boards to sit against.
Once the book is rounded and backed the spine can have endbands (headbands) attached, in this case they are a core of leather with thinned leather or bookcloth wrapped around it and attached at the head and tail of the book. Then its on to the lining of the spine, once again it has a light layer of PVA applied and left to dry. Secondly it has a layer of mull applied and finally a strip of kraft paper made into a tube is cut and applied to fit between the shoulders of the book. The Kraft paper hollow will help push the spine piece away from the text block when the book is opened.
After the textblock is complete the cover can be constructed, as a bradel binding is a case binding the cover can be made separately and created to fit perfectly the textblock it will be protecting. A "bonnet" is a shaped spine piece that connects the two cover boards and will be attached to the hollow on the spine of the book. It is a piece of thin card held between kraft paper and shaped to fit the spine of the textblock exactly. Once the cover boards are attached to the bonnet the cover is ready for covering. I have used Goat leather for the spines of these books, it needs to be thinned very carefully so that the turn in's of leather aren't visible on the spine of the book when it is attached. Its at this point that the cover images can also be applied, and then finally the cover and textblock can be put together completing the binding.