What type of thread is best for binding my book?
One of the most common questions that I get is “What type of thread is best for binding my book?”
The two suppliers that I use most often for binding thread are Colophon Book Arts Supply and Talas. However, many many vendors sell thread for bookbinding. I have used silk button thread for a small book, since it was the only thread that I could find in the color that I wanted. The photo above shows types of thread most commonly used to sew books. The photo illustrates that binding thread is sold in different sizes. The second number 3, 5 and so on, indicates the number of strands that are wound together to form the thread. The first number indicates the thickness. Therefore thread that is labeled 25/3 is thinner than 18/3. Most often I use 16/3 or 18/3. But every project varies and I seldom ever say one size fits all. It is best to have a variety of size and colors on hand. I am not real sure how vendors determine the first number. My best guestimation is that it relates to the length of thread need to equal a set amount of weight. I am not sure where along the way I heard this. Perhaps you can let me know the best answer.
You are right about the numbering scheme for thread.
I’m quoting an answer I found online, which quotes from Rachel Brown’s The Weaving, Spinning, and Dyeing Book, ed. 1987. I probably have other books that explain this as well, but I’m feeling lazy today.
“Cotton, linen, woolen, and worsted yarns can all be described by count. #1 describes the size of the yarn that will be produced when spinning a certain base yardage from 1 pound of fiber…. For cotton, No. 1 is the size thread that results from spinning 840 yards from 1 pound of cotton fiber. #2 would be the size thread if twice this yardage (1,680 yards) was spun from 1 pound of cotton… So the higher the number, the finer the thread.”
Different fibers might use different numbers for their base yardage, but for all fibers, the higher the first number, the finer the thread.