Doublures & Leather Joints
Traditionally doublures are associated with more elaborate bindings. They are usually leather or silk, but anything – paper, vellum etc. – can be used.
“The French word means ‘lining’ or ‘doubling of material’ . Also called ‘ornamental inside lining’” (from Bookbinding and the Conservation of Books, Matt T. Roberts and Don Etherington)
In the 19th. Century the doublure would normally be set into a rebate on the inside of the board created by the turn-ins from the covering leather and the inner leather joint. On more expensive bindings there would be a lot of gold tooling on the doublure and on the borders.
With more modern bindings the doublure usually covers the entire inside of the board. This, of course, means that the surface of the inside board must be filled in and completely smooth. Also, if leather is being used, it must be pared very thin so as not to prevent the book closing.
Because the doublure leather is edge to edge it is possible to carry the design over from the outside to the inside which can make for a very attractive lead into the book.

Alternatively a plain piece of beautiful suede can be used. Paper is also an option, although a traditional marbled paper does not sit comfortably with a contemporary design, I feel. If paper is used it is more commonly referred to as a ‘topper’.
They are actually quite easy to do, although I’m probably about to make it sound more complicated.
Bear in mind that you will need to have made a leather jointed endpaper with the extra thickness of paper inserted to create more space in the joint. (See previous entry).
Putting down leather joints.
Remove the extra spacing paper in the endpaper make-up.
Open the board and rest it on pressing boards. Ideally one would have a piece of felt against the outside of the board.
Remove the waste sheet, and check that the inner joint area is clean.
Bring the leather joint over onto the inside of the board and, holding it in place, make a bevelled cut from the corner of the board and 45degrees from the edge. This bevelled cut should go through the leather joint and also through the area of leather turn- in that will be underneath it. Remove the two little triangles from these pieces – the leather joint should then fit neatly against the turn- in.
Do this at head and tail. If the joint leather is thinner than the turn- in leather a piece of paper can be cut to fit between each turn- in directly under where the joint will go.
To stick the joint down I usually use pva. Initially I will remove the pressing boards so that the book board can open up completely. After no more than a few seconds replace the pressing boards and carefully rub down the joint through paper.
The length of time needed before closing the board will vary, depending on atmospheric conditions. Using pva, I find I can close them after just a few minutes. Test it by closing the book to the board. If bubbles appear, open it again, rub them down and wait a little longer.
If you leave it too long the board will get sucked down and it will look, from the outside, as if the book has been overbacked as the outer joint will be too high. If this happens insert a couple of strips of paper between the inner joint and the endpaper, close the board, gently dampen the outer joint area and carefully rub it through paper.
Leave the book between clean white paper and pressing boards under a weight.
Putting down doublures
When the book is covered and the leather joint is put down, trim each edge and fill in the space with paper that will come up to the leather thickness. I find that acid free 300gsm blotting paper often does the trick.
Sand this area smooth and cut a piece of paper approximately 1mm smaller than the board on each edge. I use an acid free kraft paper about 125gsm. Edge pare all edges of this piece and glue it onto the inside of the board. When dry, this too can be lightly sanded. You now have the prepared surface for the doublure.
Cut your leather slightly larger than required and pare it all over as thin as you can manage. Either use a spokeshave or paring machine. Smaller books are easier!
Now cut a piece of thin card, again about 1mm smaller on each edge. Place the leather on a cutting mat and place the card on top of that. With a steel rule and sharp knife cut the excess leather down each edge. You can swivel the whole thing to make each cut easier. Just be careful not to move the card on the leather.
Minimally edge pare the leather all round.
It can now be dampened and pasted and applied to the board. With paste there is time to adjust the edges so that they are straight, and aligned with the very edge of the board.
Because there are several layers being placed onto the inside of the board I find it is not usually necessary to pull them first. I’ll normally use pva for the first infill and the lining, then paste for the leather doublure.
I let it almost dry open. After about an hour I’ll close the board onto clean white paper and silicone which can be changed regularly.
Edge to edge doublures have the added advantage of covering the corners of the turn ins – just in case they haven’t gone exactly as you might have wished.