Calculating Thread Length for Coptic Stitch Binding

Sewing a multi-needle Coptic binding can be a frustration if you find you’re running out of thread. Starting off with too much can result in loops and tangles too. I have a formula for calculating how much thread you need. I wrote this in my notebook with no reference as to where I saw it. From experience I know it to be a good formula and I’m sorry I can’t credit the right person but thanks to whoever it was.

1. Measure the distance between two holes.

2. Multiply this number by the number of signatures in the book.

3. Lay the book you’re binding on its back and measure the distance from the table to the top of the front cover i.e. the height of the spine. If the book was standing on a shelf this would be the width of the spine.

4. Multiply this number by two.

5. Add the results of steps 2 and 4.

6. Multiply this number by three.

7. Add 6 inches for knots and a bit of leeway.

For a four-needle binding you’ll need two pieces of thread each of the calculated length.

I have an Excel chart with the above steps in the ‘down’ column and every time I make a new book or album I add it to the ‘across’ row at the top. This way I have information amounting to far more than the length of thread I’ve used. I also record dimensions in my notebook.

I’m sure that anyone who’s taken a course in bookbinding learnt in six months what it’s taken me three years to teach myself. I’m happy to pass on any techniques I use and you can be assured they will have been well tried and tested.