The first thing my dad asked when he saw this book was "Hmm, is that sturdy?" I don't remember how I responded but my answer to that question is, YES. Vellum is wonderfully strong yet can be rather difficult to work with. My short take on the process -- animal skin soft and wet stretched out so far and thin that the fibers are petrified and harden. Stiff, tough, awesome. I bound Jost Amman's Cuts of Craft-Workers. The book is sewn on alum tawed leather thongs which are weaved through the vellum case, which can be removed and/or replaced if need be. A rough edge gilt the top edge of the book. For rough edge gilding you must mix up all the pages very well and then apply gold solidly to the edge. Once the process is finished and the pages are placed in their original order the edge no longer looks like a brick of gold but instead shimmers gently and subtly. Pretty.