The term “conservation binding” gets thrown around a lot. It certainly sounds different than just rebinding a book. But what does it really mean?
It is unknown who coined the term, and a google ngram search shows its use beginning in the 1960s, and peaking in the 1980s. It wouldn’t surprise me if it actually started in the 1950s in England. The 1980s were the peak of rebinding in book conservation, which resulted in many treatments that we would now consider too invasive. But the ethos then was to treat a book so that it would last 500 years. Of course, the correlation between the use of the term and making a conservation binding is not known.
The trouble is, it doesn’t have any agreed upon meaning, similar to the even more ubiquitous term “archival”. All the usual suspects for bookbinding terminology — Language of Bindings, Carter, Etherington, The Multilingual Bookbinding and Conservation Dictionary — don’t have an entry for conservation binding. In practice, it can simply mean a binding done by a conservator. And anyone can call themselves a conservator. Or it can often mean a reversible layer of paste and Japanese tissue on the spine of a fine binding. Or it can imply the use of durable and modern conversationally accepted materials (i.e. linen, handmade paper, tawed skin) incorporated into a binding, with minimal attention paid to decoration and finishing.
So here is my first stab at a definition:
A conservation binding is a rebinding that is structurally similar and aesthetically sympathetic to the time the text was printed. It is durable, easily reversible, non-damaging and alters the original binding materials as little as possible. It does not fool someone into thinking it is an original binding, though it is harmonious with actual historic bindings.