Friday, November 28, 2014

Gold and Silver in Tapestries

The best argument for the timing of the spread and use of DRS spinning technology is the use of gold and silver in tapestry yarns.

Spinning such yarn is difficult to produce with good quality using the various kinds of spindles, or single drive flyer/bobbin assemblies, but is easy to produce using differential rotation speed controlled spinning equipment.  This can be easily demonstrated experimentally using the wire manufactured for wire wrap prototyping.  It is not cheap, but it is less expensive than real gold or silver wire, and has many similar physical properties to well annealed silver or gold (see for example

Spindles and single drive flyer/bobbin assemblies tend to accumulate twist on a stop and go basis depending on the fiber's capacity to accumulate and distribute twist.  Metal wire does not accumulate twist.  The properties of  wire require a continuous process with no periods of yarn lock.  This is very difficult to achieve with spindles or single drive flyers, but is the normal and standard operating condition of DRS controlled flyers.

Thus, where we see industrial quantities of tapestry yarns being produced containing gold and silver, we can presume that DRS spinning technology was available.  This is reasonable, as such tapestry yarn production also used silk, which provides a direct link back to origins of the DRS technology in the Italian silk industry.

Anywhere you see gold or silver as part of the material in a tapestry, you can be sure that DRS spinning equipment was used to produce or wind the yarn.

Certainly wire can be core spun with fiber as in or

Intertwined: The Art of Handspun Yarn, Modern Patterns, and Creative Spinning

 By Lexi Boeger.

However, one purpose of gold and silver in tapestry yarn was to provide more luster to the textile. Frequently, the gold or silver yarns were prepared by wrapping a silk core with a spiral of a flattened band of the metal.  This is the opposite of the modern "fiber-wire" craft.

Producing such yarns with a single drive system requires the takeup from hell, and some kind of a braking device on the silk core. However, once the width of the metal band is defined and whorls made, with DRS, the process is easy and fast.  Both the silk core and the metal band are supplied from reels. The metal band is wrapped around the silk with no twist inserted into to the metal band upstream from the point where the metal is wrapped around the core.  Twist is inserted into the core and must up run up stream from the point where the metal is wrapped around the core.  If the metal band is ~2 mm wide, then about 12 tpi are likely to be inserted into the core. The twist issue limits the use of short fibers such as wool and cotton.  With silk, one can start with -6 tpi, add 12 tpi and end up with 6 tpi which is reasonable. Short fibers cannot go through 0 tpi and remain competent. And a short fiber core with enough twist to be competent, will be over twisted if 12 tpi is added.

The elasticity of silk with the extensibility of the metal spiral make the metal wrapped, silk core lighter, stronger for its weight, and more weavable than solid metal or twisted filigree metal wire constructions. The need for elasticity for weaving limits the use of the bast fibers such as linen or hemp (a spiral metal band around a no-stretch core results in a rigid structure.)

The next time you see a "history of spinning", ask yourself if the history is consistent with the manufacture of yarn for tapestries.  The history of  tapestries with their known provence, industrial scale of production, and severe technical challenges are a good test for any history of spinning.

Do you really think some contract spinner in her cottage is going to have large amount of gold, silver and silk sitting around for making tapestry yarns?  Any history of spinning that does not include the production of tons and tons of tapestry yarns is incomplete.


Marlowe said...


Since when has silk acquired elastic properties? Also what proof do you have to support your assertion regarding DRS and metal yarns made in the Middle Ages or prior for that matter? Honor the standards set by scientists and provide citations. Yes, I am asking for proof and not some half-assed remark that fails to address the issue.

Aaron said...

Silk is considered elastic compared to the bast fiber. See any introductory text on textile fibers. In Amos it is pg 32, the intentional spinner talks of "structural resilience" on page 22. Think about what structural resilience in silk and linen and what it means.

The standards in science are for paid work. A scientist is paid to do research and one of the tasks included in the scope of work is a paper. In my case, I was often paid to do research and one of the tasks in my paid scope was to maintain confidentiality and make sure that nobody except the client, the client's attorney, and the appropriate regulator had access to any of the information. Much of the work that I did for US DOE is classified. You cannot read it, but it is still science. These days, most published research is behind pay walls. If you want to read most modern science papers, you pay.

When I fund my own research, I set all the rules. If you want to set the rules, then fund the research.

If you want lessons on how to locate documents, then expect to pay for the lessons.

purplespirit1 said...

I'll gladly pay for lessons to locate the documents you hold true that you "reference" for this blog.