How Linen was Made
In the 9th millennium BC, the flax plant was domesticated in the Middle East, and cultivation spread over a wide geographical area, from southwestern Asia into Europe, the Nile Delta and western Asia. It is commonly assumed that flax was originally cultivated for its seeds and seed oil. The use of flax for linen presumably began in the 8th millennium BC, and in Europe this is believed to have taken place in the 5th millennium BC.
Read more about flax cultivation here.
Flax Cultivation in Scandinavia
The earliest evidence of flax cultivation in Scandinavia is from the Early Bronze Age (1800–1100 BC), in Odense, Denmark. Seeds and seed capsules are found at several more sites throughout southern Scandinavia, most of them dated to the Late Bronze Age. Flax seeds found at archaeological sites from this early period are traditionally interpreted as indications of flax cultivation as an oil seed crop.
Fiber Extraction in Scandinavia
The oldest recorded linen textile fragments are from the early Roman Iron Age (0–160 AD), coming from the island of Bornholm in the Baltic Sea. At several locations, «retting pits» are detected, interpreted as direct evidence of processing flax for textile production. These are dated to the Late Bronze Age and early Pre-Roman Iron Age (800–250 BC). This places the start of linen production in Scandinavia well before the Iron Age.
Fiber extraction and Processing the Iron Age
What is our knowledge based on?
The information presented in this article is based on archaeological excavations from the Iron Age. This is supplemented by our knowledge of techniques and tools from the Medieval Period. The first written accounts considering flax and linen production come from this era. Based on this, researchers can make an educated guess of how linen was fabricated during the Viking Age. In addition to this, we will draw on relevant practices from later periods, such as the pre-industrial age.
Another thing to consider is the high level of regional variation, which undoubtedly was the case. This would apply to the methods used for cultivation flax, the types of tools which were used, as well as variations in the execution and order of the different processing steps to make linen.
Extraction and Use of Flax Fiber
Archaeological evidence regarding the exploitation of flax for fiber includes linen products, such as remnants of nets and cloth. Analysis of the linen can indicate its origin, and also whether we are dealing with trade or local production.
An indirect signal of possible plant fiber processing are finds of relevant tools such as heckles and spindle whorls. However, these do not necessarily indicate whether they were used for plant fibers or animal fibers.
A much more precise indication is given by flax processing debris, like shives. «Shives» is a term used to denote the non-fiber parts of the stem. These parts are removed during the process of fiber extraction. The finds of shives at settlement sites, therefore, are taken as proof of fiber production at the site itself.
Other traces of retting practices, such as «retting pits», are interpreted in a similar fashion. They give a clear indication of the use of the water retting technique. When water is used for retting, the plant material has better conditions for surviving, compared to «field retting», which leaves almost no archaeological footprint. The aforementioned retting pits started to appear in southern Scandinavia in the Bronze Age, continuing into the Iron Age. The number of retting pits found at several locations also indicate large-scale and specialized production of fiber fabric.
Processing Flax Straw
When it comes to the other parts of the production process, the archaeological sources are more scarce. From historical times (i.e. the Medieval Period and the pre-Industrial age) we have good knowledge on the techniques and the tools which were used. Similar tools have been found at Iron Age settlements, and their use in flax processing has been suggested by scholars.
The tools and techniques which are known from the Medieval Period were remarkably stable in the centuries to follow. Because of this long-standing tradition and stability throughout the pre-industrial age, we can argue that these techniques and tools must have been quite efficient, and also supports the possibility that they were used in the early Medieval Period and in the preceding centuries/eras.
Flax Plant Fiber
And how to extract it
To extract the fibers from the flax plant, quite an elaborate process is necessary. In short, the aim is to remove the seeds and the shives (i.e. the non-fiber parts of the stem). This is done with the help of microorganisms, a process called ‘retting’. The retted flax is called straw. The flax straw is then taken through several stages to remove all waste: «breaking», «scutching», and «hackling», so that one was left with only the fibers, what we call line fiber or linen. The fiber is then spun into a thread or yarn.
The Fiber Cells in the Stem
In the young flax plant, fiber cells begin to develop when the plant gets its first fully-developed leaves. The first 2 to 5 cm of the stem, which has no leaves, does not have fiber cells. When the flax stem still has a green color, the fibers reach a maximum length. According to research done in Northern Ireland, the yield of the flax straw and fibers is the highest when the stem turns yellow. The highest quality fiber is obtained in the transition from green to yellow, at this point the fiber is fine and the level of lignin is lower compared to when the plant has turned yellow.
The fiber cells are held together by pectin and lignin, which act like a glue, and form fiber bundles. In order to extract the fibers, this «glue» needs to be dissolved. This technique is called retting, and is explained below.
The flax stem is a few millimeters thick, and has a waxy cuticle surface. As we can see in the cross-section picture of the flax stem, the fibers lie in between the outside and the wooden core of the stalk, in bundles of 10 to 40 fibers. At its center, the flax stem is hollow.
Growing, harvest and drying
The first steps
Harvesting, or 'Pulling' Flax
When flax is cultivated for its fiber, it is harvested relatively early, before the seeds have matured. Instead of «harvesting», it is called «pulling». This is a pretty accurate term, because the plant is literary pulled up by hand, roots and all. This is done to increase the fiber length.
Drying and Removing of the Seeds
After the harvest, the flax plants are divided in bundles and put out to dry. This could be done in several ways. They could be placed upright in the fields, stacked, or hung on wooden frames or other constructions.
If water retting was chosen as the next step, the seeds (and leaves) would be removed at this point. From the excavation of a «retting pit» at Helstedgård Sydvest in Denmark, flax stems were retrieved. These stems had their upper and lower parts, but no seeds or seed capsules were found in the pit. This is also an indication of the removal of the seeds before the flax stems were placed in the retting pit.
In the case of field retting, it is likely that the seeds were removed after the field retting was completed. Especially if the seeds needed time in the field to mature, this would be a likely course of action (see also the explanation here).Some of the seeds were stored for next year’s crop, while the rest could be used in food by removing the capsules from the seeds. Both flax seeds and seed capsules have been identified in the indoor stable area of longhouses and interpreted as being used in animal bedding and fodder.
Today, several methods of retting are known and similar methods could have been applied back in the Iron Age to remove the seeds. The removal could be done by hand, for example beating the flax bundles against a hard surface (like a wall or table) to loosen the seeds. Special tools would be very helpful to remove the seeds. From historical records, it is evident that a ripple tool was widely used. A «ripple» is a comb-like tool which peels off the seed vessels from the stem when the flax was drawn through it. Another type of tool would have been a wooden club with a flat head, used to knock the seed vessels out.
Making flax straw
To loosen the fibers from the rest of the stem, different «retting» techniques can be applied. As mentioned before, this is necessary because the fiber cells are held together with pectin and lignin, kind of like a glue. Instead of single cells, groups of cells are formed, which are called ‘fiber bundles’ call «fiber bundles». Retting is needed to dissolve the pectin and lignin. It is basically a partial rotting process, with enzymes causing the rotting either by microbes (water retting) or fungi (field retting).
I will briefly explain two retting techniques which we assume were common in the Iron Age: water retting and field retting. In general, water retting results in a higher quantity and quality of fiber compared to field retting.
The period necessarily depends on several factors, and the retting technique required close monitoring. If the retting period was too short, the fibers would be too difficult to extract. If the retting period was too long, not only would the outside of the straw start to rot, but also the fibers.
The retting process results in a change of color of the flax stems: from green to a pale yellow color with water retting. With field retting, mildew can affect the fibers so that they turn a dark grey color.
The retting process results in a change of color of the flax stems: from green to a beige (écru) or greyish colour.
Field retting is also known as dew retting. With field retting, the stalks are laid out in a thin layer over a grass field, forming rows. During the fermentation process, various fungi work to break down the stalks. The breakdown of the material surrounding the fiber bundles is a result of bacteria, sunshine, air, rain, and dew.
In order for the microbes to work evenly on both sides, the stalks needed to be turned over on a regular basis. Another possibility would be to spread the flax stems out more (so that the ground can still be seen between them). The flax straws would be laying there for 3 or up to 8 weeks after which the straws were raked up and stacked to dry.
Water retting meant that bundles of dried flax stems were fully immersed in stagnant or (preferably slow) running water. [starting with “Both” with such a list of items makes the sentence confusing”] Natural bodies of water could be used, such as ponds, rivers, and bogs, in addition to man-made retting pits and vats. These pits were dug to reach the ground water or filled with water from a nearby water source.
Flax is very light and had to be weighed down in the water. This could be done with stones. Excavated retting pits in Denmark sometimes had stones which were likely used as weights.
Depending on the temperature and mineral content, the bundles had to stay here for several days or up to 2 weeks. Water retting required regular checking because the aim was to dissolve the outer layer— not the fibers!
Then, the bundles were taken out of the water. At this point, they gave off a very unpleasant smell and were therefore rinsed with clean water. Afterwards the retted straw would be dried, which made the smell completely disappear.
Smell and water contamination by Water Retting
It comes as no surprise that Iron Age retting pits are often found at a distance from the settlements. Because water retting happens under anaerobic conditions, the pectin materials and hemicelluloses in the flax decompose and form fatty acids, most of which are butyric. Butyric acids are also found in sweat and excrements, so one can imagine the smell. Afterwards, when the retted straws had been sun-dried, these volatile fatty acids underwent decarboxylation and decompose, losing all odor.
Besides the gut-wrenching smell, water retting also contaminates the water. It can become poisonous to flora and fauna, including humans. This meant that it was not preferred to ret flax in fishing or drinking waters.
In the case of retting pits, it meant that new retting pits had to be made after a period of usage. With time, more retting pits were constructed in the vicinity of the settlements (though at a distance). This can also help to explain the high number of retting pits at some sites in Denmark (around 30 retting pits per site), although it also points to a specialized, or even commercial, production.
From the Medieval and pre-industrial eras, several laws and restrictions are known which prohibited the use of specific rivers (e.g. those used for fishing or drinking water) for water retting of flax.
Retting pits can be described as wet pits: waterlogged pits which were dug and filled with water (rainwater, ground water, and additional water from nearby streams). Analysis of the pits found in Denmark from the Bronze Age to the Iron Age give the following general impression: they are simple structures, sometimes pits dug in the ground, sometimes with a lining of wood or bark (often re-used building material). They are circular in shape, measuring in average 1.5 m in diameter, with a depth of up to 1 m. Some pits have wooden ladders.
Sediment samples from the bottom layers of these pits— with the help of plant macrofossil and pollen analyses– showed that they contained stems, seeds and capsules from flax, seeds from hemp and nettle and pollen from hemp. Sometimes even hole bundles of flax stems were found at the bottom. Interestingly, in some pits both hemp pollen and flax remnants are present, indicating that the pits were used for retting both plants. (Read more about the use of plant fibers here).
Drying the Straw - again
The retted stalks are called straw. The flax straw had to be thoroughly dried. This could be done in the open air, drying in the sun, for example by laying the straw out in a field, or other techniques, as was described above. Of course, it would be highly dependent on the weather and wet fields or rainfall would lead to the opposite of the desired result.
Another way would be the use of an oven or drying pit, which are well documented from the Medieval Period. Because of the fire hazard, the flax had to be closely monitored. A drying pit could be constructed as a deep hole in the ground in which a fire was started with a grill on top on which the flax was dried. Another possibility would be to create to pits, and have the heat and smoke channeled to the pit where the flax is placed on the grill (to diminish the fire hazard).
From Straw to Spinnable Line Fiber
The Process Step by Step
After the retted straw was dried, many more steps had to be completed before the fibers were ready to be spun. As previously noted, we have limited knowledge about the techniques of how the straw was treated in the Iron Age. The Medieval Period (and also the whole pre-industrial period), has many sources indicating that different types of tools were used, in addition to the methods used and the particular order in which they were done. We will use the Medieval sources as a starting point.
The treatment of the flax straw
The processing of the straw would presumably begin with breaking of the stalks. Freshly broken flax was then 'scutched'. The final step before spinning is a technique called «heckling». This led to a material that was ready to be spun. From this moment on, it is no longer called straw, but «linen».
A byproduct (or perhaps better described as a «waste product») of extracting the fibers from the flax stem would be the wooden, non-fiber parts of the stem. These are called shives, shoves, or boon. The extraction of the fibers would entail a considerable amount of shives. We can imagine that these shives were not regarded as waste, but were used in different ways, like for livestock bedding, as an insulation material, and so on.
When shives are found during archaeological excavations, this is commonly interpreted as evidence of flax processing for textile production at the site. An example is the Iron Age site of Feddersen Wierde on the northwest coast of Germany. Here, small piles of broken flax stems were found, which were interpreted as indications of breaking and scutching practices that took place here in the Iron Age.
The first step towards spinnable bundles was done by breaking the stalks. The breaking of the flax straw can be interpreted quite literally, as the stalks were beaten until the woody part began to loosen from the fibers.
For the breaking part to be easy, it was crucial that the retted flax was dried properly. It is therefore likely that the breaking was done immediately after the straw was dried, in order to avoid the flax absorbing moisture from the atmosphere. The exact moment for this would depend a lot on the retting technique used, but it would be in the late autumn or the beginning of winter (around November).
Breaking can be done by hand. However, special tools can be a helpful aid in this process. Archaeologists have found the remains of different types of tools, and one of their proposed uses could be for the breaking of flax. These tools can be described as wooden clubs, sticks, or mallets, some with indentations along the edges. Following this interpretation, they were «breakers», and used to pound on the flax.
Another device, which we are familiar with from the early Middle Ages (early finds from northern Germany), is the so-called «flax breaker» or «flax break» (Norwegian bråk).This is a wooden device which functioned as a large chopping machine. The flax is placed in between two wooden 'jaws', the upper jaw being a type of lever which could be opened and closed. The jaws could have incisions or grooves (especially seen on the flax breakers from the later Middle Ages). The flax was moved while the handle was pushed down, in order to break it from root to tip.
Traditional 19th-century flax breaker, a large wooden chopping device. Bundles of flax were pounded and broken by the blades from the root to the top. © Greve Museum, Hedebo Embroidery, www.hedebosying.dk
Breaking flax with a wooden club. © Martina König https://exarc.net/issue-2020-2/at/flax-fibre-extraction-techniques-late-middle-ages
Now, the broken straw needed to be completely removed, which required a technique called ‘scutching’. At this point, the fibers were released from the wooden stem.
Perhaps the stalks were pulled between two wooden sticks? Another possible approach would be the use of a special knife (Norwegian skakekniv) and a scutching board, as we are familiar with from the pre-industrial period. These boards are best described as upright standing boards. Examples from the 17th century show a tradition of exquisitely ornamented wooden boards.
To remove the last impurities, a so-called ‘heckle/hackle’ was used. This tool would also straighten out and align the fibers, so that they would be facing the same direction.
Hackled flax is soft and has a shiny appearance to it. After several rounds of hacking, the fibers were ready to be spun into a thread.
A hackle is like a type of comb with very long teeth, or tines/prongs. Evidence from the Medieval Period shows that it was a wooden board with nails standing upright. Medieval depictions show women placing the hackling comb against their knee, pulling the flax through the comb. Some hackles even had an opening on the lower end as a toehold.
The spacing of the tines varies, and they can be lined up in different ways. Usually, one would begin with a rough hackle (wider spacing) and then move to a finer hackle (closer spacing).
During the Iron Age, such tools with long iron teeth (placed in several rows) appeared, and archaeologists often interpret these tools as hackles.
During the Medieval Period, another processing step is recorded. A process called «smoothing» could be done right after breaking (replacing the scutching step), after scutching, or even after the hackling. This could be done with what is called a smoothing knife, in order to align the fibers and smooth them to fine, silky bundles. A smoothing knife could have wooden handle and a dull blade – so as to not damage the fibers. A bundle of flax straw was laid on top of a piece of leather (placed on the thigh) and worked with the smoothing knife.
The End Result
Tow and Line Fiber
Finally, the labor- and time-intensive process had almost come to an end. Beginning with the sowing in spring, the harvest in august, and the drying and retting process along with extraction of the fibers throughout the autumn and early winter, around the start of the new year, the spinning could finally begin.
The residues which are left in the heckle are called ‘tow’. Hackling would result in quite an amount of tow. Tow fibers were short, and of lesser quality compared to line fiber. However, we can assume that the tow was not thrown away. Instead, it was likely used to make a more coarse yarn for rough clothing. Tow fiber can also be hackled once more in order to get more usable fiber.
About 10–15% of the weight of the flax straw would result in line fibers. The finest line fiber would be the result of a very fine hackle with close-set pins. The wreaths were stored for spinning. To keep the elasticity in the line fiber a longer storage period would be beneficial. After spinning, the linen could be bleached in the sunlight, which was likely done in the springtime.
The Use of Linen in the Viking Age
and suggested further reading
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König, Martina. ‘Flax Fibre Extraction Techniques in the Late Middle Ages’. EXARC Journal 2 (2020) https://exarc.net/ark:/88735/10501
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