On leaving things alone
People bring us a book and apologise for it. The spine has gone, the boards are hanging by a thread, somebody's grandmother wrote in the margins. They expect us to make it look new, and they are usually a little relieved when we explain why we would rather not.
A book is a record of its own use. The grease on the lower corner of a prayer book, the slight lean of a cookery book that has spent sixty years propped open: none of that is damage in any sense that matters. Damage is what stops the book from opening, or what will make it fall apart next year. Everything else is history, and history is hard to put back once it has been cleaned off.
So the first question we ask is what the book needs to do. A family Bible that is read once a decade needs less than a working dictionary. A volume going to a collector needs a different treatment to one going back on a kitchen shelf. Often the right repair is one new sewing support, a Japanese tissue hinge, and a box.
We use wheat starch paste and animal glue, because they can be undone by whoever comes after us. That person may know more than we do, and we would like them not to curse us. Old endbands stay if they can. Old leather stays if it can be consolidated, even when it looks tired. New leather, when it has to be new, is toned to sit beside the old, without pretending to be it. Look closely at our work and you should be able to see what we did.
This takes longer and costs more than a smart new binding. It also looks less impressive in a photograph. We have made our peace with that.