Bookbinding - A method of attaching covers to a book. A tab of spine material is laminated into the cover boards for an exceptionally strong join. They are no older than the Sixteenth Century, when tape-sewn books were invented.

Split boards are not suitable for bindings sewn on exposed cords (the cords would have to go from the outside of the spine to the middle of the covers, which would not lie at all well). This covering style is difficult (but possible) for books with tight joints, because the hinge comes in the middle of the cover thickness (rather than on the outside, as with lacing on). This provides some blockage to the smooth opening of the book.

How to cover a book with split boards

This explanation assumes you have a rounded and backed book block sewn on tapes, two sheets of thin cardboard, and two sheets of thick cardboard, all cut to size. Note that the thick cardboard will go on the outside of the book.

  1. Laminate the boards

    You need to paste the thin board and the thick board together. Draw a line on each thick board, about 4cm from the spine edge. Brush wheat paste on the board from that line to the fore edge of each board.

       |4 cm|        
       |    |        |
     s | n  | p      | f
     p | o  |  a     | o
     i | n  |   s    | r
     n | e  |    t   | e
     e |    |     e  |
       |    |        |
       |    |        |

    Lay the thin board on top of the pasted thick board, and slip a piece of waxed paper in the unpasted bit (just to be sure). Put both sets of cardboard in a book press or under a heavy weight for a day or so.

    You now have something like this, viewed cross-sectionally.

      --------------- <- thick board
           PASTEPASTE <- thin board
  2. Create the tab

    Time to do a little work on the book block now. The plan is to paste a tab of book block material into the split of the boards you've just laminated. But first you have to make that tab.

    If you've sewn the book on tapes, then the tapes themselves are sticking out on either side of the spine. If you've padded the back with fabric and kraft paper, then you also have a bit of cloth sticking out on top of the tapes. And if you've made your endpapers with an eye to this process, then you have at least one waste leaf to spare on each side of your book block. Time to paste them all together.

    Brush wheat paste on the waste leaf. Then stick the tapes down, and brush more paste on. Stick the cloth down, and add yet more paste. Last of all, fold the waste leaf over on itself, fore edge to spine edge, covering all your paste, tapes and fabric over. Slip some aluminium flashing in between the tab you've created and the book block (otherwise you'll dent the pages) and put the whole thing in a book press for 24 hours with just the spine sticking out.

  3. If you're making a tight joint, chamfer the spine edge of the boards.

    Nicking the corners won't be enough to relieve the pressure when using split boards - you must chamfer the entire spine edge. Cut it at a 45° angle with a sharp knife. Make the chamfer no deeper than half the thickness of the thick board, or the joint may crumble with time.

           thick board      
            thin board
  4. Paste the tab into the split boards

    Once everything's dry, it's time to put things together. Cut the tabs back to 3 1/2 cm long, and clip their corners. Brush wheat paste inside the split boards, taking care not to crease the thin board as you open the split. Then slide the tab into the split and close the thing up. Take a moment to align the book block. If you're doing French grooves, use whatever form of grooving rod you will use on the final cover to get the correct spacing.

     1    2     
      \ |||||    \
       \|||||     \   thin board this side
       CU|||UD---- ===============
         UUU          thick board this side
    1.  Tab constructed in step 2
    2.  Book block

    Again, slip aluminium flashing in between the boards and the book, and press for at least 24 hours. The book is now ready for covering, if the spine is complete.

You can also attach a book sewn on buried cords to split boards. Just fray the cords out so they lie flat when creating the tab.