 Books are bound starting from leaves, sheets of paper, or in the past of parchment, so different materials mean different techniques to create the book. After folding these sheets you end up with sections that are made of bifolia. Those sections are then joined together through the passage of thread with a needle and they can be sewn on supports or simply through stitching. They're joining them on the back, so on the folds. Byzantine binding have sewing unsupported, so made of sections that are joined together simply with the passage of thread with a needle. Byzantine bindings are very peculiar because of some specific physical features they identify them. First of all the boards are flashed with a book block. They're lined up with something that is not like a western book where you have the squares as we call them, so the boards are attached at the end of the sewing actually protrude from the book block. The most striking feature is the end bend. The end bend that protrudes from the book because it's sewn on top at head and tail, so top and bottom, and it's done outside what I said, the boards and the book blocks. There are other smaller details, like one very unique, I would say, are the grooves along the edges of the wooden boards, head, fore-edge and tail, and we don't really even know exactly why. This is just made for a statical reason. This one specifically is 15th century, as I said, central manuscript, so still in the time when it's considered the pure Byzantine style. We can immediately see this very peculiar feature where the end bends, head and tail protrude from the height of the entire book block. In the original one we also have a very nice decoration of the edges of the boards, and this again is quite typical of Byzantine binding. These are the reproductions of the original tools that were used to decorate this binding in the 15th century, so you can actually see from this you gain that impression.