I happen this morning to be working on a small quarter-calf re-back, where the spine leather is completely missing and the first few millimetres of the side leather is also fragile and discoloured. Standard method would be to cut into the side leather where it is still sound and use a lifting knife to create a slot into which new leather can be tucked and glued.
But that means that at the hinge the new leather will be glued down on to degraded old leather before being tucked under the side leather. Not a good idea to glue something on to a flaky or powdery base. Bernard Middleton’s method, as set out in his ‘Restoration of Leather Bindings’, is to remove the degraded strip and replace it (so as to avoid a step or lip at the edge of the ‘good’ side leather) with a strip of thin card the same thickness as the side leather, thus:
Jim Brockman once told me that this was known in his workshop as ‘the Bernie Strip’. I make a point of passing that phrase on to anyone who ask how I do my repairs.
After the new leather spine strip has been glued and tucked into the slot and well pressed down you get a perfectly flat surface with a neat join.
The result is a hinge that will hold and last. As will Bernard’s legacy.