What do the Sizes of Linen Thread Actually Mean? It’s Complicated.

Some common sizes of linen thread for bookbinding, ranging from 18/6 to 80/3.

Bookbinders likely know that linen thread is classified by a two number system, such as 35/3. And most know that the second number represents the number of threads plied together, and the first number how thick or thin the thread is.  But what does the first number actually refer to?

It turns out that two different systems, an English system and a Metric system that use a similar two part description of size separated by a forward slash. However, these two systems are not the same. Most thread sold by bookbinding supply companies uses the English System.

The English system (aka. Number English, Lea, NeL, Linen Count) is based on how many skeins (of 300 yards) make up one pound in weight. I *think* this means that twelve  12/1 skeins would weigh one pound, or thirty-five 35/1 skeins would weigh one pound. I’m still not sure how adding the plied threads results in the classification. Would a 35/3 thread weigh 3 pounds?

The Metric system (Nm, aka. the Japanese Gunze Count) is based on how many meters of thread weigh one gram.  So I think for a 60/1 thread, 60 meters weighs one gram. It is the same as the English system in that overall, thicker and stronger threads have lower numbers.

Other thread systems include:

Tex — How many grams 1,000 meters of a thread weighs. In this case, the larger the number, the thicker the thread.

Denier — How many grams 9,000 meters of a various thread weights. Again, the larger the number, the thicker the thread. This is useful for very thin threads and microfibers.

Grist — Yards per pound.  For example, a 20/1 linen is 3,000 yards long per pound. Different fibers have different weights.

I’m still not sure what system the Londonderry Linen Lacing Thread in the image above uses. It is labeled only a mysterious “#4”. I love sewing with this thread, though, since it is thick, soft, easy to untwist, tangle free without waxing, and remarkably compressible. It is possible to sew a book naturally packed with it. It consists of five plies, and is roughly equivalent to a 20/5.

If you are wondering what size thread you should use to sew a book, check out my Guide to Swell.

Finally, Colophon Book Arts is a reasonably priced, one stop shop to purchase a wide variety of sewing threads.

Wait, there are more systems  … AARGH!      https://en.wikipedia.org/wiki/Units_of_textile_measurement



Cor Knops, of Knops Boekrestauratie in the Netherlands,  kindly sent me these images of some antique thread he owns.


Great name!

These packages contain hanks of thread, and all weight about a pound.  I think the package on the left is 25/3, and on the right 12/3. So if my calculations are correct, the 12/3 should contain 1200 yards of thread, assuming a 12/1 would contain 12 – 300 yard skeins = 3600 yards.  Enough thread for a lot of books in any case!

Interview with Jeff Peachey from NTD Television

A couple of weeks ago, Shiwan Rong and her crew from New Tang Dynasty News interviewed and filmed me in my studio. I recounted how I entered the field of conservation, explained some of the differences between conservation and restoration, and demonstrated a few bookbinding techniques. It was interesting to see what made it into the final cut, and despite some quibbles, overall it presents a reasonably accurate summary of what I said., considering that a three hour interview was cut down to two minutes!

One of the first questions was something like “How does it feel to be a master craftsman in the dying art of book restoration?”. This allowed me to explain that first of all, I am not a master craftsman, though I suppose anyone can call themselves one. Secondly, I discussed the differences between restoration, conservation, and bookbinding. Finally, I argued that the study and importance of the material nature of the physical book is thriving, not dying, in a large part because we as a society are not dependent on books simply for textual information. All in all, I hope the interview can educate the general public a bit about books and book conservation.

The video is accompanied by a written article and still images:

Treasures from a well made book: NY book conservator saves books for the future.


An Unusual Sewing Frame from the Roycroft Bindery

A very unusual sewing frame. Roycroft Campus, East Arora, New York.

I was excited to find a small display of bindery tools at the Roycroft Campus in East Aurora, New York.  Elbert Hubbard started Roycroft, was inspired by William Morris, and promoted the Arts and Crafts ethos in America during the first part of the 20th century. His press produced many books that today look aggressively “hand-made”.

The sewing frame from his bindery, however, is strikingly innovative and elegant.  The support attachments are similar to the Hickock blank book sewing frame, which I think was designed and produced at least by the 1920’s. I’m uncertain which came first. I use a similar idea for clamping supports in my Nokey Sewing Frame. The curved and cantilevered uprights allow for arm clearance and stability. The late 20th century Clarkson sewing frame uses a similar design.

The rod in the front might be to wrap tapes on, so they can be continually fed upwards.  It also looks like the rod itself can slide a bit in a recess, to the weight helps apply tension?  There are two hinged areas, the front one may also trap the supports, and the one towards the back may contain a storage area? There is some residue on the rod, suggesting something was adhered at some point. But what and why?

The uprights can be removed, and the frame stored in the wooden box it rests on, like the Clarkson design. Given the aesthetics and the use of oak which is common in arts and crafts furniture, but uncommon for bookbinding tools, I would guess  it was made at Roycroft.  But the bindery display contained many other pieces of equipment from other sources, including a very nice Leo Finishing Press, so it may come from another source. It is a clever and compact design.