Birka Tentrad: The Rediscovery of an Ancient Process

Birka Tentrad: The Rediscovery of an Ancient Process
Display at An Tir Kingdom Arts and Sciences/Bardic Competition 2017

This was my single entry from An Tir Kingdom A&S/Bardic Championship 2017. There are some redundancies from my previous blog posts because I wanted to give a full picture of posament to the judges. My focus this year was on the creation of tentrad. I have also included a PDF version of my documentation.

Disa i Birkilundi Tentrad Documentation 2017

Birka Tentrad: The Rediscovery of an Ancient Process

Posament made with .25 machine made tentrad


Posament is a beautiful and complex embellishment technique that has become my passion over the past three years. It is found almost exclusively in Birka, Sweden and dated to the 9th and 10th centuries. This complex and beautiful combination of wirework and embroidery is uncommon even in Birka.

Though both gold and silver wire was used to adorn items in Birka, I will be focusing on the type best known by the name posament which is generally a silver wire coiled around a silk core. More specifically, I will focus primarily on the creation of the cording used to create the posament generally referred to as tentrad.


I used several different materials during my research process.  During my previous research and recreation of the Birka decorative art known as posament I first used a commercially available tentrad.  This is a silver colored wire wrapped around a fiber core that can be imported from Sweden. At the time, I felt this would best represent the original pieces as it is still used by the indigenous people in Sweden to create similar items. Later, I decided to explore how tentrad was made in Birka during the middle ages.  To my surprise, I quickly realized that very little research had been done on this subject and that no extant tools or evidence of techniques has been discovered.  I set out to do my own research into the possible tools, materials, and techniques used to make this beautiful and rare textile.

Materials used in tentrad process

Extant posament is made with primarily with silver wire wrapped around a silk core (Geijer, 1938). While creating my own tentrad I used a variety of wires and core materials. I used 28, 30 and 32 gauge silver-plated craft wire as well as 28 and 30 gauge dead soft silver wire. For the core of the tentrad I used hemp, cotton and silk threads of various sizes.


There are no tools that have been found that are exclusively associated with the creation of tentrad. Most of the items that could have been used would have most likely been items also used for other tasks, such as needles, pins and drop spindles. I used both a 1mm and a .7mm circular knitting needle with a coiling gizmo to create my tentrad using one technique and a drop spindle for the second technique.


Grave Finds

My first goal was to get a better idea of what posament was used for and how it was created. I contacted Lotta Fernstål, Early Iron Age Senior Curator at the Historiska Museet in Stockholm, Sweden. I had spoken to her previously about a piece of wire weaving that is on display at the museum and she had been wonderfully helpful. Her colleague Anna Arnberg contacted me and said that Lotta was not available but she would be happy to help. Anna spoke to the textiles curator to get further information on the pieces. She was told that the posament was most likely attached to some kind of clothing but that unfortunately none of the textile was found so they can’t be certain. She also said that posament has been found on things like scabbards and purses. From my own research, I knew that the pieces are generally found in the waist and head areas. Posament being present in the head area indicates that it was also most likely used in hats and headpieces as well. Anna also provided me with a link to their online database showing all the graves that have been excavated in Birka.

Map of Birka Gravesites (Museet, 2011)

Having access to the museum’s amazing online database gave me an opportunity to see where each piece of posament came from. I wanted to get a better sense of just how rare posament was and if there was any sort of pattern in where it had been found. I was hoping to determine if it was something that everyone had access to or if it was reserved for those of higher status. The database is broken down into several sites on Birka. It gives you access to 1,103 graves that have been excavated and lists the inventory of each one including any photos of the pieces if available. I went through each grave individually so that I could note which graves had posament present as well as the type of grave it was found in (Museet, 2011).


There are four different categories of graves found on Birka. Chamber Graves are the largest and are primarily from the 10th century, they generally have more grave items found within them. Coffin and Non-Coffin graves are from both the 9th and 10th centuries (Ringstedt, 1997). The Coffin Graves are more modest than the Chamber Graves but many items are still found and the Non-Coffin Graves are found with the least amount of items. Cremation Graves are also from both the 9th and 10th centuries and the items found can vary widely with many having no items found (Ringstedt, 1997).

Posament 2

Out of the 1,103 graves, I found 44 (3.99%) contained extant posament. They were found in each grave type however 55% were found in Chamber Graves even though they were only 10% of this type of grave found on Birka. With such a large majority of the pieces being found in Chamber Graves it would make sense that this was something more common in the 10th century as that is the period of time they were utilized. According to research on the Chamber Graves significance in Birka they were not necessarily reserved for the wealthy but it is believed they were intended for those of high status in the community (Ringstedt, 1997). This means that though posament could be found in small amounts throughout the community it was more likely to be found with those of higher status.


Type E posament with units of measure (Museet, 2011)

While looking through the photographical inventory of the graves I realized that there are very few pictures of posament indicating size (Museet, 2011). I found a few with units of measurement on the side of the photograph and so I blew them up to actual size. What I discovered surprised me. Some of the pieces were larger than I had initially assumed. The tentrad itself looked to be up to just under a millimeter and the pieces themselves were up to two and a half centimeters tall. I had always pictured these pieces being much smaller than this and the recreations that I have found online were made with the factory-made tentrad that is available in Sweden which does not come in that large of a diameter.


Type G posament photo taken by Amica Sundstrom (Sundstrom, 2015)

I contacted Lotta Fernstål once again to inquire about the size of the tentrad itself as well as the size of the pieces. She was able to get me in contact with Textiles Curator Amica Sundström. Amica was able to send me a picture showing the size of one of the pieces. Unfortunately, it’s a bit blurry and the ruler isn’t directly up against the piece making it difficult to determine the size. The photograph is of a much smaller piece than the ones that I had been looking at previously and I find the variety in sizes that were found very interesting. This gives a large range of possible sizes for the tentrad.



The Sami are the indigenous people that live in Northern Sweden. I first became interested their connection to posament and the people of Birka when I started looking for a material to use to create my first pieces. Tentrad is a material made in Sweden that the Sami use to create beautiful bracelets as well as to adorn clothing, scabbards for knives and bags. The work that the do today is very similar to the work done in Birka in the 9th and 10 centuries.

When I decided to create my own tentrad I thought I should look further into if the Sami make their own tentrad and if so how. My hope was that their technique might give me some idea of how the people of Birka created their town tentrad.

The only piece of information that I was able to find in English regarding the Sami and tentrad was both exciting and frustrating. The statement was simply that some of the old crafts people still make their own tentrad. I realized that the only way to get any real information was to get some help from someone who spoke Swedish.

I met Linda Wåhlander through a Facebook posament group. She works at Historiska Museet as a Museum Educator and has been incredibly helpful with translations, leads, and as someone to talk to about what I’ve been learning. I asked Linda to if she could help me research the technique that the Sami use to create their tentrad. She was able to find a webpage that had a small overview of the process of drawing the wire and materials used but no real information on how the wire was coiled onto the silk.

Sami woman using a drop spindle to create tentrad (Huldt & Hoving, 1920)

Linda then found an exciting book about Sami crafts called Mönsterbok för lapsk hemslöjd i Västerbottens län (1920). The book has a chapter with a step by step breakdown of the tentrad creation process with pictures. The book is all in Swedish (I have done a rough translation of the tentrad chapter and it will be included in the appendix) but the pictures are all that were needed to make the connection. The Sami use a drop spindle to coil the wire onto the cord. This was an incredibly exciting discovery! Drop spindles were a tool used by the Norse and it makes perfect sense that they would also use this technique to create tentrad.


Posament can be broken down into a few different styles of knots. I will use the labels listed in Birka III  for each of them; A,B,C,D,E,F,G and H (Geijer, 1938). These eight types are used in different configurations in most posament. For example, the piece that I created using silver and silk tentrad created on a needle was a combination of H and F style knots. This was based on a piece found in grave 1125.7

The pieces are almost exclusively worked using a double strand (Geijer, 1938). I only recall seeing one extant piece that uses a single. Working with two strands does not seem to have any sort of structural advantage. I believe that the double strand was used simply because it looks nicer and appears more complete, complex than the single.



Initial Experimentation

When I began my research into posament I initially worked with machine made tentrad. Machine-made tentrad is a silver-colored wire with a synthetic core. As I progressed in my research, I found I wanted to make tentrad myself using the materials found at Birka.

I started by making a piece entirely by hand. I wound 26 gauge craft wire around a piece of hemp cord to get the idea of what this would entail. I was able to make about a foot of cord which was enough to make a small piece of E type single-cord posament. The tentrad was a bit uneven looking and difficult to manipulate. I also ended up with a rather large blister on my finger and decided there must be a better way to do this.

Working on a Needle

I did a lot of research online on how tentrad could be made. There are machines that spin a fiber and run the wire down it creating guitar cords. This was a possibility but since there have not been any real posament tools found I felt this was not the right way to go. I started looking at making micro coils and realized that a Coiling Gizmo might be a good place to start. I purchased a professional style coiling gizmo because it came with a pin vise that I could use to work on any sort of rod. It also came with a 1mm rod that I could start experimenting with.

The first process that I tried with the Coiling Gizmo was coiling wire directly on the cord itself. This didn’t work very well as the cord was constantly getting twisted and the unevenness was showing up on the outside of the tentrad. I was having to stop working every few minutes to untwist my cord.

I tried 28 and 30 gauge silver plated wire and settled on the 28 because it has a little more strength and is less fiddly. The 28 gauge also looks like a more accurate ratio between the size of the thread and the size of the coiled wire with the size of the tentrad I was able to make.

During this process, I used three different types of cores: cotton, hemp and silk. I can understand why silk was used as opposed to any other fiber. The silk moves so smoothly that it makes the creation as well as the knotting processes much easier.

I began working with the 1mm rod to see if it might work. The rod was only about 16 inches long which was not long enough to create anything very useful so I decided to make the coil by starting on the end of the rod and working my way toward the pin vise. In this way, I could simply push the coil off the end of the rod and continue working. This process created a much more uniform look that was much more accurate to the extant pieces. I was able to make several 3 foot pieces of tentrad and used them to create B and G type knots. Though I was able to get longer pieces, there was an issue: even if I worked the wire in the opposite direction (as suggested by the tool) I could still only create a piece of tentrad a few feet long. The issue was that in order to add the fiber core I had to thread a piece of wire all the way through the coil in order to bring the fiber back through. This only works up to a certain length as eventually your wire will get stuck in the center of the coil. The only way I could solve this issue was to make the coil on a rod and then push it off directly onto a cord.

My next thought was to thread the silk through the eye of a needle so that I could push the coiled wire off the end of the needle and directly onto the silk. As I could not find a way to drill a hole in a 1mm or smaller rod, and long needles that I tried ended up sticking due to their shape, I decided to try a circular knitting needle. Circular knitting needles have a plastic piece attached to the end that I could use to hold my cording therefore there was no bump for the coil to get stuck on like the eye of a needle. I found 1mm and .7 mm metal circular knitting needles and decided to give them both a try. I cut the plastic cord in half and then poked a small hole in the plastic piece near the end to run my fiber through. The process worked very well! I was able to make a 145 inch piece of tentrad out of 28 gauge craft wire on the first try. It takes 1,440 inches of 28 gauge wire to make 115 inches of 1mm tentrad or 144 inches of .7mm tentrad. This is 12.5 inches of wire per inch of tentrad for the 1mm and 10 inches of wire per 1 inch of .7mm tentrad. Each piece of over 100 inches in length takes at least six hours to complete.

Setup for needle method

My process became to take a small strong beading thread and run it through the hole in the plastic, I then coiled my wire onto the rod, pushing it off onto the cord as I went. When the piece was complete, I removed it from the rod and attached my silk thread to the end of the beading thread. The coil was then slid onto the silk to make the finished tentrad.

I created several pieces of tentrad with this method using 28 gauge craft wire and silk thread. When I was confident enough in my method I used the dead soft silver wire and was able to finally create my silver thread with a silk core.

I used my silver thread to reproduce my favorite extant piece of posament. It is a combination of H and F style knots. I have only found one picture of the original piece. The photo is in Birka III and lists it as coming from grave 1125.

I was able to get the posament section of Birka III translated from German and was excited to discover that they had also thought that the wire may have been wound on a rod or needle.

Extant posament from grave 1125 (above) and reproduction using needle method tentrad (below). (Geijer, 1928)

There were, however, several issues with this process. The coil of wire is very fragile until it has the silk thread inside; the thread keeps the coil from being undone. This creates an issue when you are trying to make long pieces of tentrad and are unable to move the wire onto the silk until it is complete. The second issue is that the people of Birka created tentrad much smaller that I had been able to. I hadn’t seen any needles found that would be small and strong enough to make such a small finished cord. It didn’t seem logical that they would have used this method though it was very exciting that I had been able to create pieces using silver and silk rather than the machine-made tentrad.

The Drop Spindle

Comparison of needle method tentrad (left), drop spindle tentrad (center) and .25mm machine made tentrad (right).

After additional research into the Sami I was able to extrapolate a process that makes much more sense and is actually still used by the indigenous people of Sweden today. Though there is no certain evidence that the Sami and the people of Birka had contact the fact that the items used in this process are all things that would have been available in Birka makes this technique much more possible.

I began my experimentation into this process by trying different sizes of wire and silk. There are many different sizes of tentrad that have been found but my goal was to find a combination of sizes in wire and silk that would look correct and be strong enough not to break. After working with several sizes of silk and wire I determined that a 30 gauge wire (.25 mm) and .42 mm silk thread would fit these requirements. Though the silk is technically thicker than the wire the silk becomes much thinner during spinning and is still thick enough not to break easily.

Hand placement for spinning

Once an appropriate wire and silk size had been determined the process itself was relatively simple to work out. Using the drop spindle method, the silk and wire are attached to the drop spindle and wound around the hook. The drop spindle is held in one hand while the silk and thread are held by the other. Without dropping the spindle spin it in your hand and hold the wire and silk in a way that makes the wire wrap around the silk. Spin the drop spindle as many times as you are comfortable with (I do about 30 at this point) then hold the spindle under your arm while you pull the loose wrapped wire together making the coil. Wrapping the wire loosely around the silk gives the tentrad extra flexibility that it wouldn’t have if the wire was coiled. This is one of the issues I had during my previous experimentation.

Twisting the wire loosely onto the silk

Using this process, you are putting the wire under more stress. This can cause an issue because the wire that is being worked is so thin and it has a tendency to break. With the needle process, it was much more difficult to add additional wire to your work which was a major hindrance if you were not able to get very large lengths of wire. While using a drop spindle I only have to uncoil a small amount of the wire so there is something available to add on to and then simply twist the end of the old and the new wire together.

Working on tentrad at Kingdom Feast 2016

Another problem that is solved with this technique is time management and transportation. While coiling around a needle I had to sit and coil almost nonstop for hours at a time to avoid the coil being destroyed before the silk was added to the core. There was no way to move a piece once you were in the process of creating it. This is no longer a concern when using a drop spindle as you are putting the wire directly onto the silk. Because of this you can coil up the tentrad that you have made onto the drop spindle, coil up your silk and wire onto their respective bobbins and stop for the day or transport it to another location. I have worked on tentrad at home, work, in the car and even on the train!


The idea put forward in Birka III was also my initial thought; the wire must have been coiled on a needle. However, after the research and experimentation that I have done I feel confident that the drop spindle method is a much more probable way that the people of Birka could have created tentrad. The needle method is far too cumbersome and delicate to have been used for any length of time. I also don’t see it being possible for them to have had a needle small and strong enough to make the smallest size tentrad. The drop spindle method is easily transportable and could be set down at any time to work on other tasks. In just my first attempts with the drop spindle method I’ve been able to take the size down by over half because I wasn’t limited by the tool that I was using. I hope with further practice I can reduce the size down even further.

I look forward to further exploring the world of posament and tentrad. My next adventure is to delve into silk and silver. I plan to learn how to draw my own silver wire and reel silk hopefully using tools that I’ve created as well.  My goal is to be able to create a piece of posament from raw materials to completion.

Posament type E created with four different types of tentrad. From top to bottom: tentrad made using the needle method, tentrad made using the drop spindle method, .35mm machine made tentrad and .25mm machine made tentrad


Works Cited

Arnberg, A. (2014-2015). Curator, Historiska Museet. (A. Harding, Interviewer)

Fernstål, L. (2015-2016). Senior Curator, Early Iron Age, Historiska Museet. (A. Harding, Interviewer)

Geijer, A. (1938). Birka III, Die Textilfunde aus den Gräbern. Stolkholm: Almqvist & Wiksells.

Gustafsson, A. (n.d.). Välkommen till tenntrådshantverkets historia! Retrieved from Ateljé Agnes:

Huldt, H. H., & Hoving, F. (1920). Mönsterbok för lapsk hemslöjd i Västerbottens län. Hälsingborg: Schmidts boktryckeri. Retrieved from Historiska Museet.

Museet, H. (2011). Sök i Historiska museets samlingar (Search History museum collections). Retrieved from Historiska:

Neumann, M. (n.d.). Retrieved from Silberknoten:

Ringstedt, N. (1997). The Birka Chamber-Graves – Economic and Social Aspects: A Quantitative Analysis. Current Swedish Archaeology, Vol. 5.

Sundström, A. (2015). Textiles Curator, Historiska Museet. (A. Harding, Interviewer)

Wåhlander, L. (2015-2017). Museum Educator, Historiska Museet. (A. Harding, Interviewer)



Appendix 1: Translation of selection from Mönsterbok för lapsk hemslöjd i Västerbottens län (Huldt & Hoving, 1920)

Translation done by Andrea Harding (HL Disa i Birkilundi) with assistance by Linda Wåhlander

The tin rod is flattened with a hammer. An ax head rammed in to a chopping block and then works well as an anvil. The tin rod needs to be straight at all times, otherwise it will break. The hammering must be smooth, so that no sharp edges can occur. As in old times melting the tin in to round bars, makes the material brittle.

The flattened tin rod is cleaved in two with a knife or an ax against a chopping block. An unprocessed tin bar can also be split in the band saw. The edges of the two split tin rods are carved smooth and round with a knife.

The coarse tin tang is pulled with pliers through the draw plate holes. In order to work with the tin the room should have a temperature between 25-30 degrees Celsius (86 degrees F,) which makes the tin soft. Drafts can impair performance. At the first it is hard to draw. You can use your feet as help. Another way in is to attach the drawplate in a vice and draw the coarse thread with pliers.

Drawing must be done smoothly and methodically, otherwise the thread breaks easily. Drawing should preferably be done all at once, because if you leave it the wire blackens and becomes more fragile to work with when the heat has gone out of it. Before the thinnest thread is finished, it has gone through approximately 60 holes with increasingly smaller diameter. The finest holes widen over time due to wear and must be replaced with new finer holes taken up with an awl. From half a tin rod you can draw up to 50 m of spun thread, if one is skilled. The drawn wire is laid in large loops on the floor and rolled, when the procedure is completed, on a reel.

The wire is twisted around upholstery thread (in older times a sinew). Inner wire should be similar in diameter to the drawn tin thread. Is it too thin relatively to the tin wire it breaks. The tin thread and inner thread are held in your left hand while the drop spindle is spun between your right forefinger and thumb. With your left hand grasps the tin wire with your thumb and forefinger and let the inner thread rest over the little finger. At the twisting the tin wire folds thinly (wide) around the inner wire so that it must be guided (pushed) together to completely cover the inner thread. With your right hand you push together the twisted tin wire down along the wire and with the left hand holding the inside wire stretched using the middle finger and tin the wire with thumb and forefinger.

A small piece of the already twisted wire always untwists when pushed tight (when tightened up). The spun thread is after contraction (tightened and pushed along the inner wire) often uneven and must be smoothed by twisting between the right-hand thumb and index finger.

The finished tin wire is then wound up on the drop spindle. When then tin wire is to be spliced, the already twisted outer end on the already twisted yarn and new thread are joined by twisting them together. This “knot” will remain until spun past the junction, then the “tied knot” can be cut off.


Appendix 2: Translation of selection from Birka III (Geijer, 1938)

Translation by Katrine De Saint Brieuc

VIII Passementerie

Ingenious knots and braids, either alone or in combination with each other, sometimes in conjunction with other needle techniques, are found abundantly among the Birka textiles.

Technically, this work is not exactly the same thing as is understood in later times by the word “passementerie” (French passement). Since it does coincide with the general character of this more recent product of this kind, it would not be unjustified to use the same name.

The then passementerie from the Birka graves in respect of technique consist mainly of continual braids with different number of strands (see Figure 21 a – d), which are usually freely “woven” and then drawn together, partly decorative knotting, which is indeed a form of braiding, the tying of these knots, when taut, served no practical function. The ornamental junctions are produced by means of one or two strands, which are laid in curves and then threaded or worked in sequence over each other. In some cases, it is doubtful which of two names, braids or knots, is the more correct.

Probably the threads in both the braids and knots were of a kind wound on a rod, giving a means of supple function, so that they would be suitable for the work.  One can easily imagine that the beautiful bone needles of different shapes that were found in the soil of Björkö (Plate 39) were used for this very purpose. One can further assume that in some cases a firm support base was used for guiding the “weave”, to a certain extent a very simple counterpart to the lace pillow of later times, with its pins. In any case, the resemblance between the braids P 1-7 (Plate 27) and the simplest bobbin lace work is striking, although it would be wrong for other reasons to apply this definition here. Here all the “strands”, namely the threads that are pulled back and forth, are unlike bobbin lace, but rather woven with free pieces.  The decorative knots are always flat and made with the same system, where the pieces are regularly braided over and under each other.  In form they are often square. Often they are combinations of the two smallest knots ( e and g in Figure 21). Figure 21 occurring types of braiding and decorative knots

The material in the resulting work is either smooth gold, often quite coarse, or, more rarely spiral gold and only in exception cases spun gold. In contract silver occurs almost exclusively as spiral thread, (about the material see page 68), moreover executed with remarkably even precision.


Appendex 3: Translation of Välkommen till tenntrådshantverkets historia! (Gustafsson, n.d.)

Translation done by Andrea Harding (HL Disa i Birkilundi)

Tin Wire Jewelry has a very long tradition. Already during Viking times adorned it with their possessions spun thread of gold, silver and bronze. They have found dies of horns during excavations at Birka and Sigtuna. They have also found fragments of spun gold thread that has been dated to about the year 1000 before Christ.

Among the Sami tin wire work has been widespread since the 1600s. They probably had the idea to spin tin wire when they traded with the Scandinavians, mainly with the Norwegians. Most commonly they were using silver thread but Sami began using tin because it was easier to process and moreover was less expensive than silver.

Man-made thread by a birch or other wood was cut in half and the center was removed. Then the band branch together with string. A mixture of tin and lead which solidified was then poured in the hole. The rods were then pressed through small holes drilled in reindeer antler slices until you got the desired thickness. When it had been sufficiently thin tightened it around reindeer sinew after which the wire was finished and could be sewn in beautiful patterns.

In the 1800s handwork disappeared almost completely, and probably it was because for some time the Laestadian* movement denounced tin (as well as silver.) They felt that if they were faithful they were not allowed to decorate themselves with “pomp and ornamentation”. Eventually, the craft disappeared from the southern Sami areas and at the beginning of the 1900s there was hardly anyone who engaged in this craft.

1905 Andrew Wilks found Dikanäs his mother’s old tin wire tools and began experimenting. He managed to finish both pulling and spinning tin wire. Probably it was his merit that this dying art form was saved.

Today the craft is extremely popular and one sees one variation after another. Much is based on the same grounds but there are also very innovative samples too.

*A conservative Lutheran movement.