There are two basic knots used in book repair – the weaver’s knot and the square knot.

Weavers KnotThe Weaver’s Knot
Since sewing with a very long piece of linen thread can be difficult, the weaver’s knot is used to tie on additional lengths of thread so shorter lengths can be used.
Tie on additional thread when there is about 6” of thread left on the needle. Tie the knot inside the signature, as close to the last sewing station as possible. A knot cannot easily pass through a sewing station hole so it should lie between the sewing station holes on the inside of the signature.

  • Make a loop of the remaining thread and hold it in your left hand, with the short end of the loop on the bottom.
  • With a new thread, make a loop with the short end on the bottom and hold it in your right hand.
  • Insert the left-hand loop underneath and into the right-hand loop and hold both in place with your left thumb.
  • Take the short end of the right-hand loop under and through the left-hand loop
  • Pull the short end of the left-hand loop and both ends of the right-hand loop away from each other until the knot is secure. Trim both ends.

Square KnotThe Square Knot
Square knots are used to tie off sewing thread when resewing a text block or attaching materials into binders.

  • Take one end of thread in each hand.
  • Pass the right-hand thread over the left hand thread and through the loop. Pull tight.
  • The original right-hand thread is now on the left side. Place it over the right-hand thread and bring it through the loop. Pull tight. Trim the end of the original thread. Do not cut the added thread.