My friend Amy is scheduled to teach a workshop on Springback Binding in a few weeks, and asked me if I would help work out the timing for some parts of it. It's not a structure that I've made before, so I was curious to see how it all came together. And I like working on things with her! We had one meeting to go over the initial steps in the structure and discuss where students may run into problems and some of the timing of things. And then I got too excited about the whole thing!
I worked with a book that was converted from individual page .pdf form into a paginated collection of 4-folio sections. This was I would have a completed, real book instead of just a "model" book. The sewing took a bit (as this was a thick textblock) but after that it all went quite smoothly. The main obstacle I encountered was drying time - I was anxious to continue!!!!
The flange for this thing is magnificent - it's got SO MUCH stuffed into it and ends up being ridiculously stiff. The leather is easily applied and didn't stretch too much. It took seemingly forever to dry though.
And it works!!! And I'm thrilled with it. I'm a fan of books with slightly-too-thick covers, so I love this structure. The opening mechanism is great - you can feel it "pop" the textblock out of the spine.
The springback binding is most commonly seen in old account ledgers. The "spring" allows the spine to pop out and lets the pages all open flat, straight across the gutter. To do this you create a magnificent lever that is incorporated into the binding. The boards for these books are generally quite thick, and the spine is solid as well. The leather applied to these books was traditionally only edge-pared, allowing for a little bit more stability with the thicker leather.