Bookbinding - the oldest form of book construction still in common use, sewing on exposed cords is one of the standard techniques of the professional fine bookbinder. It is difficult and finicky in places, and is therefore somewhat less popular with amateur binders.
How to tell if a book is sewn on exposed cords
A book sewn on exposed cords will normally have a flexible binding and tight joints. Anything with a hollow back or French grooves will not be sewn on exposed cords. Once you have elimnated these features, there are two places to look to check if the book is sewn on exposed cords.
- The inside of the signatures
To determine this, look inside the book. Find the centre of a signature, where the stitching is visible. If the stitches all but join up, with the thread coming into and out of the same hole, then the book is either sewn on exposed cords, or stitched together without cords or tapes at all. (Contrast this to a book sewn on tapes, where there will be about a 1cm gap between stitches, and one sewn on buried cords, where a bit of the cord is visible.)
| \ / |
| \ / |
| | |
| | |
| | |
| · <---- tiny gap - book is
| | sewn on exposed cords
| | or stitched with no tapes
| | or cords
| | |
| · |
| | |
|________________ | ________________|
- The spine edges of the covers
Books sewn on exposed cords generally have their covers laced on. This process leaves small V-shaped marks on the covers where the cords from the spine go into the boards.
| V V V V V |
Note that the V-shapes may or may not line up with the bands on the spine. A bookbinders may add false bands in between real ones, or even hide the real ones and add false ones in other positions, depending on the decorational requirements of the bookbinding.
How to sew a book on exposed cords
- signatures, ready for sewing
This style of sewing is not suitable for tipped on endpapers, so you will need some form of "made" endpapers already glued up.
You can use cotton or linen cord for this. Whatever the fibre content, the cord should be 2 - 4 milimeters in diameter. If it's made of cotton, be sure to pre-shrink the cord by washing it. Otherwise the cord will contract when you paste the cover on the spine and your book will no longer close.
Linen thread is best, but cotton or polyester will also do for non-archival work. The thread should be strong - if you're using cotton or polyester, make sure it's button thread.
Tools & Equipment
- sewing frame
Unlike sewing on tapes, you can't sew on cords without a frame. If you don't have one, you can turn a chair on its back and thread your cords over its rungs.
- small saw (if you plan to do kettlestitches)
I use a small tenon saw, bought from a hardwares store. (I saw Norm Abram use an identical one to saw a dovetail, so it must be good.)
- piercer or bodkin
You'll need rather a large hole for this sewing, because the thread goes into and out of the same place.
- a thick needle
- beeswax (optional)
Drawing the thread you're going to sew with over a cake of beeswax will prevent it tangling. You can get small blocks of wax for this purpose anywhere quilting supplies are sold.
- Mark the book block
Decide how many cords you want to sew on. The traditional number is five, but smaller books can be sewn on fewer. Decide if you want a row of kettlestitches at the head and tail. Stack the signatures, adding the endpapers at front and back. Mark all lines on the backs. Make sure the signatures, endpapers, and lines are all square.
- Saw for the kettlestitches
Remove the endpapers from the book block. Use your bodkin or piercer to stab holes on the kettlestitch marks for them.
If you have a cutting press, clamp the rest of the book block into it, making sure the back is even. (Otherwise, just hold the book block firmly, again ensuring the back is even.) Saw a shallow groove along the kettlestitch lines at the head and tail. The groove should have a squared-off "U" profile, and be just deep enough to reach the innermost page of the signature.
Take the book block out of the press.
- Pierce the signatures
Use your bodkin or piercer to make holes in all the marks on the backs of the signatures. Be careful not to tear the paper, and ensure the point comes out on the inside fold of the inner page of each signature.
- Set up your sewing frame
Decide if you want single or double cords. That's just what it sounds like - do you want on cord at each marked position, or two? You can bind with some single and some double cords - make your decision based on the aesthetic balance of the final result.
Whichever you choose, attach them at top and bottom to line up with the holes on the backs of your book block. Single cords should hide the holes, doubles should straddle them. Check that the cords are square and tight enough to hum when plucked.
Z=====|===||===|======Z <- bar
Z | || | Z
Z | || | Z <- threaded rod
Z | || | Z
Z ==|===||===|== Z \
Z ==|===||===|== Z book block
Z ==|===||===|== Z /
Z Z \ bottom plate
Sewing table set up with 3 sets of cords, 2 single & 1 double. Cords are tied to the top bar and masking taped to the bottom plate.
- Begin Sewing
If you're sewing kettlestitches, pass your needle in through the kettlestich hole on the bottom endpaper, leaving a couple of inches of tail hanging out. (Otherwise, pass it in through the first cord hole) Bring it out through a cord hole and wrap it around the cord. See the diagrams below for how to wrap the thread round single or double cords.
_______ ______\ /
\ / /
--------X-------- back of signature
| O |
_______ ______\ /
\ / /
--------||-------- edge of signature
/ || \
| O || O |
Unlike sewing on tapes or sewing on buried cords, you cannot draw the thread tight at the end of each row with this technique. You have to tighten it as you wrap it around the cord each time.
- Sew the Second Signature
When you get to the end of the first signature, the thread will come out of the rightmost hole. Take another signature (ensuring it is the right one, and the right way up) and lay it on the first. Push the needle into the rightmost hole of the second signature and start sewing, wrapping the cords the same way you did on the first.
When you get to the leftmost hole, you will have a thread hanging out from each of the first two signatures. Tie them together, pulling up any looseness.
- Continue Sewing
Put another signature down, checking that it's the right one and the right way up. Sew along it like before. When you get to the rightmost hole, if you're doing kettlestiches, do one here.
Just keep adding signatures and sewing them in.
- Finish Sewing
When you have sewn the final signature down, do a couple more kettlestiches to tie the thread off. Detach the cords from the sewing frame and admire your book.
Note that you cannot tighten the cords once you've sewn using this technique.