The Language of Silk Fibers Demystified

New to spinning? Maybe spinning is a newfound interest and you want to test various fibers? Foxed by the terminologies such as ‘Roving’, ‘Sliver’, ‘Top’? Let us demystify them for you!

One can weave with a number of natural fibers – like wool, cotton, silk and so on. In this post, we will make it easier for you to understand the technical terms used by silk weavers. Let us start at the very beginning with a basic question - which is...

How Do You Get Silk Yarn?

A few special varieties of caterpillars of moths make cocoons just before they turn into moths. You may have heard about this, right? The cocoon is made of a fiber that is processed and turned into silk yarn. 

Let's Take a Quick Look at How This Process Happens

The stages in the life cycle of a moth are:

1. Eggs - Eri silk moth lays eggs.
2. Silkworms - Eri silkworms become hungry caterpillars.
3. The pupa is formed inside the outer layer which is the Eri silk cocoon.
4. The moth emerges from the cocoon to lay more eggs.

          
Stage 1                Stage 2

          
Stage 3                  Stage 4

The cocoon is nothing but a ‘hollow, oval house’ that the caterpillar builds for itself to hide in while it transforms into a moth! The fiber is ejected by the caterpillar through its mouth and in such a way that a hollow, oval covering is created. It shakes its head vigorously tracing the figure of ‘8’ and seems to ‘blow’ out cotton candy textured fiber! One of the many miracles of nature. This stage is also referred to as a pupa.

Human beings have found a way of harvesting the fine fiber that forms the cocoon, spinning it into yarn and weaving silk cloth! Smart is it not?

The Four Types of Natural Silk

There are four types of moths that produce silk:

1. Bombyx Mori L– produces Mulberry silk
2. Antheraea produce Tussar silk
3. Antheraea Assamensis produce Muga silk
4. Samia Ricini and Philosamia Ricini. P.Ricini produce Eri silk

In the case of the first three, the moths are killed at a time that is considered the correct one to get the best quality of silk yarn – one of the things they look for is to get a long strong filament from each cocoon. Only in the case of Eri silk, the moth naturally emerges from an open-ended cocoon. It flys to mate and lay eggs before the silk fiber is collected. No wonder Eri silk is called ‘Peace Silk’. It is another matter that the caterpillars are often eaten by those who rear silkworms as they are a rich source of protein!

Did you know that close to 80 to 90% of silk in the world is Mulberry silk and Eri silk accounts for around 8 to 10%?

Muezart works in the heart of an Eri silk producing region in the State of Meghalaya, in the Northeast of India. The name of every Eri silk spinner and weaver is known to the partnership team.

Get Familiar with the Technical Terms of Preparing Silk for Spinning

Let us look at the language of the sericulture community as we walk ourselves through the steps from cocoon to woven Eri silk cloth. In Meghalaya Eri silk is a cottage industry and most of the processing is by hand. There are textile mills in the bordering state. The below process contains a description of both hand and mill preparation of Eri silk.

Cocoon: Read the entire process of the making of a cocoon. The source of silk fiber are cocoons. The staple diet of the Eri silkworms are castor leaves and tapioca leaves. Silk cocoons do vary in color, size, and texture.

De gumming: This is the first step in getting the cocoons ready for spinning yarn. The cocoons are first boiled in soapy water to remove a gummy substance and to separate the fiber strands. If processed by hand, the cocoons are then pounded and stretched out into a flat shape. A machine flattens the cocoons into silk sheets at a mill.

Cocoon sheets: Eri silk sheets are washed cocoons that have been flattened and are ready to be fed into the carding machine and spun into yarn. The sheets are carded which prepares the fiber into roving and silk top which is used for spinning.

     
The home-spinners of Meghalaya spin Eri silk yarn directly from the degummed cocoon cakes which are processed by hand and dried in the sun. Cocoon cakes are not carded. Instead, the village spinners fluff the de-gummed cocoons by hand as they spin.

Carding: It involves the cocoon sheets being fed between two rotating drums, near each other which have spikes on them, followed by a combing-like process that results in the silk fiber strands falling parallel to each other. Much like how when ladies with long tresses comb their hair to make the strands fall beautifully straight and parallel before they braid them. That is just to give an idea – not exactly what carding and combing silk fiber is all about! The degummed cocoons will have fibers criss-crossing. By carding, they are fluffed up and separated and made ready for the next step which will be spinning. 

One of our team members described what happens in a mill carding machine: “The cocoon sheets are placed on a conveyer belt and fed between the two drums. These drums have spikes and act like combs and remove ‘debris’ and fluff-up the fiber. Combing is done to make Roving and Top. After we get Roving or Top, the rest of the fiber is not wasted but spun into yarn.”

All of Muezart’s handspun Eri silk yarn is created directly from the cocoon cakes that we hand process. 

How is Silk Roving and Sliver Made?

Creating Roving and Sliver can be done by hand, or by machine. These steps describe machine processing and creating Eri silk roving.

1. After the degumming process, the cocoons are passed through a cocoon opener that spreads the cocoons into sheets. These cocoon sheets contain both the short and long fibers from the cocoon.
2. These cocoon sheets (also referred to as cocoon cakes) are passed through a small gap between two drums rotating close to each other to separate the long fiber from the short.
3. The process of combing pulls the long fiber to another part of the machine to form Silk Top and what is left are the short fibers.
4. The short fibers are further carded to make a thickish cord which is 2 to 3 inches thick. These are called Eri Silk Rovings. Narrower cords make Eri Silk Slivers. 

What Are Silk Top?

When Eri silk fiber is carded and combed, we get both long fibers and short ones. The long fibers end up parallel to each other and form silk top. Something like soft, silky, horse tail!

So, to reiterate, roving/sliver are short fibers and silk top are long fibers. The roving/sliver is used for making uneven yarn whereas the silk top is used for making finer, more even, high-quality yarn. Short fiber yarn is less expensive than long fiber yarn. Yarn is also made by blending roving and top. Through blending we can create and customize different yarn textures. The price of yarn depends on the ratio of short to the long fiber used in making the yarn. 

There are more technical terms like silk hankies, brick, noil, or laps. We will create another post on those!

Before we go, here is a trivia. Did you know that Eri silk is hydrophilic fiber?

Hydrophilic means that a fiber that loves water and can absorb a lot of it, and that means our handwoven Eri silk shawl and yarn are less prone to pilling.

What is pilling you ask?

With use some silk and woolen material develop small knots on the surface which can be unsightly! That is what is pilling.

Hydrophobic fibers (textile fibers that repel water) tend to pill more because hydrophobic fibers have more static build-up, and end up clinging together on the surface of the fabric instead of falling off.

Wool is an exception to the rule. Wool, although hydrophilic, tends to pill because the surface of the wool fibers is scaly and the scales stick to each other and to the fabric.

Did this article help demystify some of the vocabularies in the world of silk fiber? Add your comments and help by sharing your knowledge about silk yarns!

Try spinning with our selection of 4 Eri silk fibers. This sampler is put together for makers like you!