Bookbinding: convert a paperback to a leather bound

The step-by-step Instructable: https://www.instructables.com/Perfect...
My website: https://travisdanielbow.weebly.com/
My books on Amazon: https://www.amazon.com/stores/author/...
My books on Audible: https://www.audible.com/author/Travis...

Bookbinding lore can get pretty esoteric (never paste a super to a signature without a bone folder!), but it's actually pretty simple and easy to turn a $10 paperback into a leather bound masterpiece that makes a great present or addition to your collection. This is my simplest and most elegant method yet, and for the first time I recorded video of the whole process to include with the step-by-step instructions.

How this method is different:

-My first successful method used thin chrome-tanned leather over cardboard. It worked great, but you needed a laser to make any artwork on the cover, so it was a little limited in usefulness.
-My next method used a very similar structure, but I figured out a way of adding extra cardboard cutouts to the structure under the leather to make pretty cool 3D designs using thin, flexible leather. Still a great method if you're not into tooling leather.
-My last method was to tool thick veggie tanned leather for the front and back covers but use a thin, flexible leather for the spine. This worked great for rebinding my Bible (and my wife's, and my dad's, and my sister's) and holds up well, but...
-...My new method combines the lessons learned from these other methods to make the simplest, most elegant leather-binding method yet. It requires a single piece of medium-thickness leather with no cardboard backing structure. This makes it flexible enough to open easily, thick enough to take tooling (optional), and feels great in your hand.

Note: Tooling the leather is totally optional for this method, but if you want to take it on, I'll show some techniques both for the hand-crafted-art sort and for the design-in-CAD-and-make-it-perfect 3D printed sort.