To reiterate what I've taught and been taught, when you are binding books you generally need a thread that will not stretch or break
Linen Bookbinding Thread - Book Craft Supply
How To Tie A Weaver's Knot (Attaching A New Thread) - iBookBinding - Bookbinding Tutorials & Resources
Bookbinding Kit – Library of Congress Shop
Bookbinding Tools & Supplies
Unwaxed and unbleached, this 35/3 gauge Linen Thread is perfect for bookbinding. The thread comes in 50 yd. spools.
Books by Hand Linen Thread
100% cotton thread, reel with 1000 meters. ideal for sewing 90 gr paper booklets such as Cultural paper or bond paper. Hilo de Algodón Black
Thread And Needles Diy Book Binding Supplies
Getting Started Bookbinding Best Thread for Coptic Bindings
Hand-Poured and Molded Beeswax Thread Waxers
Lineco University Products Books By Hand Waxed Linen Thread 3pk
Bookbinding with Paper, Thread, and Tape - Center for Book Arts
DIY Tutorial: How to Choose the Right Bookbinding Thread
Buy 300D/16 Braiding Hollow Leather SewingThread 1.5mm Handmade Craft Leather Thread Stitching Bookbinding Shoe Repair at Aliexpress for . Find more ,
300D/16 Braiding Hollow Leather SewingThread 1.5mm Handmade Craft Leather Thread Stitching Bookbinding Shoe Repair
German Linen Thread 25/3 50 grams – Hollander's
DIY Book Binding: Perfect Binding — Gathering Beauty