The transformation from flax plant to linen fabric is a long and beautiful journey that embodies craftsmanship at every step along the way.
One of the most important steps on that journey is the retting process. Retting is essential in priming the flax plants for textile usability.
The process begins after the flax crop has reached maturity and it is pulled from the ground, but before it is collected from the field.
What is Retting?
Retting is the process by which flax fibers are released from the stem of the plant by monitored natural degradation.
Flax fibers are some of the most beautiful in the world, the problem is they come bound to the stalk of the flax plant.
The stalk of the plant holds together the individual flax fibers with binding compounds known as pectins. The goal of retting is then to remove these binders without harming the flax fibers.
Conveniently, this pectin material can be broken down by many of the world's naturally occurring microorganisms.
Over the course of the retting process, these microorganisms consume the pectin material, and as a side effect, release the individual flax fibers from the bonds that hold them together.
Day after day, the status of the decomposing flax plants is carefully monitored. Once it is determined to be of sufficient degradation, the retted flax is collected and shipped onto the next phase of the linen weaving process.
As the flax is retting, many of the fiber's final properties are being slightly altered. For example, its natural color, strength, smoothness, antibacterial properties, are all partly modified by the retting process.
How Flax is Retted
The two major retting methods are:
- Dew Retting
- Water Retting
Dew retting is the oldest and still most common form of retting in western Europe.
After the flax has been pulled, it is spread evenly in the field, and over the course of the next 3-7 weeks, depending on climatic conditions, natural decomposing bacteria work to dissolve the pectin material around the plant stalks.
This form of retting relies on the expertise of farmers to know when to begin, continue, or end the process – with much on the line, as over/under-retted fibers are of low quality for textile use. Thankfully, many European flax farms have been run for generations by farmers who have decades of expertise in the practice.
Dew-retted fibers are generally darker in color and more veritable in quality than water-retted fibers.
- Pros: natural process, chemical free, no labor involved, inexpensive, no environmental damage, more sustainable, yields more fiber, bestows greater natural antibacterial properties on the fiber
- Cons: more room for error, can produce inconsistent and poorer quality fibers if done improperly, takes longer than other retting methods, requires the use of the field for the duration of the process
How Climate Effects Dew-Retting
Climate is the constraining factor when it comes to dew retting.
While flax can be grown in most regions of the world, not many have the heavy nighttime dews and warm daytime temperatures that are required for dew retting. This is why northwestern Europe's cool, moist climate is the home of 80% of the world's textile flax cultivation.
And since most of the rest of the world is not suitable for dew retting, there must be another option.
In water retting, the pulled flax plants are immediately collected from the field and submerged in a body of water; the bacteria present in the water then degrades the pectin and releases the fibers.
Historically, water retting was performed in natural waters, such as bogs, ponds, lakes, dams, ditches or slow-moving streams and rivers. The stalk bundles would be weighed down with stones or wood for about 1-2 weeks, depending on the water temperature and mineral content. Nowadays water retting is conducted in modern retting tanks.
Similar to dew retting, the process must be monitored on at least a day-to-day basis to achieve the optimal fiber quality.
Generally, water retting produces a more consistent fiber than dew retting because conditions remain constant throughout the process. On the downside, water retting creates biological pollution, and therefore its wastewater must be treated prior to its release.
- Pros: faster process, can be performed in any season, results in a more consistent, finer, and stronger fiber
- Cons: can cause waterway pollution, wastewater requires treatment, little to no antibacterial properties in final fiber, water and labor intensive
While dew and water retting are the traditional forms of retting, there is a third, more modern but highly unfavorable method of retting – chemical retting.
Chemical retting is an increasingly frequent, modified version of water retting that involves immersing the plants in a chemical solution to increase the speed of fiber release – taking only a mater of hours.
Chemical retting is more expensive and results in a more polluted wastewater and often a lower quality fiber.
- Pros: fastest form of retting, can be performed year-round
- Cons: expensive, low quality fiber, significant wastewater treatment required, energy and water intensive, close control is necessary
The retting process is one of the most unique and important steps in the journey from flax plant to linen fabric.
The expertise and effort involved in retting alone is unmatched by most other textiles and it is one of the reasons why linen is of such exceptional quality.
As for us, we source exclusively dew retted flax fibers for our handkerchiefs. We have a deep admiration for the craftsmanship of dew retting and are always in favor of supporting sustainable and ecologically compatible processes. Additionally, dew retted flax fibers also produce a more naturally antibacterial handkerchief.