Tuesday, 12 May 2026

Silk Fabric Terms Explained — Part 2: Understanding Silk Yarns



Silk Fabric Terms Explained — Part 2: Understanding Silk Yarns

In Part 1, we created a practical map for understanding silk fabric terms.

We saw that a silk fabric name may tell us about fibre, yarn, twist, weave, finish, handle or traditional usage.

Now we will begin with the most basic layer: silk yarn.

This is important because before silk becomes chiffon, georgette, crepe, kora, habutai or matka, it first exists as yarn. The character of the yarn decides the character of the fabric.

A smooth silk yarn gives one type of fabric.

A highly twisted silk yarn gives another.

A yarn made from waste or pierced cocoons gives a very different surface.

So, to understand silk fabrics properly, we must first understand silk yarns.

In this part, we will discuss five important terms:

Raw silk, bivoltine silk, China silk yarn, katan and organzine.

Silk yarn journey from cocoon to fabric
Silk yarn journey: silkworm race, cocoon, filament, raw silk, twisted yarn and fabric. Click image to view full size.

Why Yarn Terms Matter in Silk

In cotton, wool or synthetic fabrics, yarn is also important. But in silk, yarn becomes especially important because silk is a filament fibre.

A filament is a long continuous fibre. Silk filament is obtained from the cocoon of the silkworm. Several fine filaments are brought together to form a silk thread.

This is different from cotton, where many short fibres are twisted together to make yarn.

Because silk is naturally long, fine and lustrous, small changes in yarn preparation can create large differences in the final fabric.

For example:

Yarn Condition Fabric Effect
Silk with natural gum Firmer handle, more body
Degummed silk Softer handle, higher lustre
Twisted silk Better strength and weaving performance
Highly twisted silk Crepe, chiffon or georgette effect
Waste silk yarn Irregular, textured, rustic appearance

So when we hear a silk fabric name, we should not ask only, “Is it silk?”

We should ask: What kind of silk yarn has been used?

1. Raw Silk

Raw silk is the silk thread reeled from cocoons by drawing together the required number of filaments. It still contains its natural gum, known as sericin.

This gum is important.

Sericin acts like a natural coating on the silk filament. Because of this, raw silk has more body and stiffness than fully degummed silk.

In simple words:

Raw silk is silk before the full removal of natural gum.

This does not mean that raw silk is unfinished in a careless way. It means that the gum is still present and is part of the yarn’s behaviour.

Practical Understanding

Raw silk generally feels firmer than degummed silk. It may have more body, more stiffness and less softness.

This is useful in weaving because the gum can give strength and protection to the yarn.

In many traditional silk fabrics, raw silk is used deliberately. The gum helps in maintaining body during weaving and finishing.

Why Raw Silk Matters to Merchandisers

A merchandiser should not treat raw silk and soft finished silk as the same.

Raw silk may affect:

  • fabric handle,
  • drape,
  • lustre,
  • dyeing behaviour,
  • finishing behaviour,
  • and customer perception.

If a customer expects very soft, fluid silk and receives a firmer raw silk fabric, she may feel that the fabric is not comfortable. But for certain products, that firmer handle may be exactly what is required.

So raw silk should be understood as a technical condition, not merely a market word.

2. Bivoltine Silk

Bivoltine silk refers to cocoons produced by a silkworm race having two generations or life cycles in a year.

The word can be divided into two parts:

Bi means two.

Voltine refers to the number of broods or generations in a year.

So, bivoltine silk comes from silkworm races that complete two life cycles in a year.

Practical Understanding

Bivoltine silk is often discussed in relation to silk quality, cocoon quality and filament quality.

For a textile student, the important point is that bivoltine is not a fabric structure. It is not a weave. It is not a finish.

It refers to the biological production pattern of the silkworm race.

This makes it different from terms like katan or organzine, which refer to yarn preparation.

Common Confusion

A student may think bivoltine silk is a type of fabric.

It is not.

It is connected to the silkworm race and cocoon production.

Correct understanding: Bivoltine silk is a source-quality term, not a fabric-construction term.

3. China Silk

The term China silk has two meanings.

First, it refers to a plain weave, lustrous, lightweight silk fabric traditionally produced in China and Japan.

Second, it can refer to a white raw silk yarn of superior quality from north China.

In this article, since we are focusing on yarn terms, we will consider the second meaning also.

China Silk as a Fabric

As a fabric, China silk is generally light, plain woven and lustrous. The threads may be irregular and soft. It is usually dyed or printed and used for blouses, lingerie, linings and similar products.

Historically, it was handwoven in China using mulberry silk. Later, the term was also applied to machine-made imitations.

China Silk as Yarn

As a yarn term, China silk may refer to a white raw silk yarn of superior quality.

This is important because the same term may refer to both a fabric and a yarn depending on context.

Practical Understanding

Whenever the term China silk is used, ask:

Is the person referring to the fabric or the yarn?

In fabric trade, China silk may mean a light silk fabric.

In yarn or raw material discussion, it may refer to a quality of raw silk yarn.

This is a very good example of why textile terminology must be read contextually.

4. Katan

Katan is twisted filature silk.

This is a short definition, but it is very important.

Let us break it.

Filature silk means silk that has been reeled from cocoons in a controlled way. It is generally smoother and more continuous than spun silk.

When this filature silk is twisted, it becomes katan.

So katan is not merely silk. It is twisted reeled silk.

Practical Understanding

Twist gives silk better strength, body and weaving performance.

In many fine silk fabrics and sarees, katan yarn is valued because it gives a clean, strong and elegant fabric.

A fabric made with katan can have better structure than fabric made with very loosely twisted or untwisted silk.

Katan Cloth

Katan cloth is a plain weave mulberry silk fabric in which double and twisted yarn is used in both warp and weft.

This means that katan cloth is not only about fibre. It is about the use of twisted silk yarn in fabric construction.

Why Katan Matters in Indian Textiles

In Indian saree vocabulary, katan is often associated with richness, strength and fine silk character.

But technically, the important point is:

Katan means twisted filature silk.

Once we understand this, the term becomes clearer.

It is not just a market name. It tells us something about the yarn.

Comparison of raw silk katan and organzine yarns
Comparison of raw silk, katan and organzine yarns. Click image to view full size.

5. Organzine

Organzine is a silk yarn used mainly as warp yarn for weaving or knitting.

It is made by twisting single silk threads first. Then two, three or four of these threads are folded together. After folding, they are twisted in the opposite direction to the original single twist.

The twist generally ranges from about 350 to 700 twists per metre.

This construction gives organzine strength, balance and stability.

Why Organzine Is Used in Warp

In weaving, warp yarns face more stress than weft yarns.

Warp yarns are held under tension on the loom. They pass through healds and reed. They experience repeated movement and abrasion.

Therefore, warp yarn must be strong and stable.

Organzine is suitable because its folded and balanced twist structure gives better performance during weaving.

Organzine and Organza Are Different

This is one of the most common confusions.

Organzine is a yarn.

Organza is a fabric.

Organzine may be used in making many silk fabrics. Organza is a sheer, crisp, transparent fabric.

The similarity in spelling creates confusion, but technically they are different.

A simple way to remember:

Organzine = yarn.

Organza = fabric.

How These Yarn Terms Differ

Let us compare the terms clearly.

Term What It Refers To Main Meaning Practical Importance
Raw silk Yarn condition Silk with natural gum Gives body and firmness
Bivoltine silk Silkworm/cocoon source Two life cycles in a year Related to cocoon and filament quality
China silk Fabric or yarn Lightweight silk fabric or superior raw silk yarn Meaning depends on context
Katan Yarn type Twisted filature silk Gives strength and clean appearance
Organzine Warp yarn Folded and twisted silk yarn Strong and stable for weaving

This table shows that all terms do not belong to the same category.

Some are biological terms.

Some are yarn terms.

Some are fabric terms.

Some have more than one meaning.

That is why classification is important.

A Simple Flow from Cocoon to Fabric

To understand these terms better, imagine this sequence:

Silkworm race → cocoon → filament → raw silk → twisted silk yarn → woven silk fabric

Now place the terms in this flow:

Stage Related Term
Silkworm race Bivoltine silk
Reeled silk with gum Raw silk
Superior raw silk yarn from China China silk yarn
Twisted filature silk Katan
Folded and twisted warp yarn Organzine
Plain weave silk fabric Katan cloth, China silk fabric

This is a much better method than memorising definitions.

When we know where a term fits in the production chain, we understand it more deeply.

Silk yarn terms classification chart
Classification of silk yarn terms: source, yarn condition, yarn type and fabric usage. Click image to view full size.

Technical Note: Sericin and Degumming

Silk filament has two main protein components:

Fibroin is the main structural silk fibre.

Sericin is the natural gum that surrounds the fibroin.

When silk is reeled from the cocoon, sericin is still present. This gives raw silk its firmer feel.

The process of removing sericin is called degumming.

After degumming, silk becomes softer, more lustrous and more comfortable. But before degumming, the gum can help the yarn during weaving.

So the decision to use raw silk or degummed silk is not accidental. It depends on the intended fabric and process.

Practical Note for Buyers and Merchandisers

When dealing with silk fabrics or silk yarns, it is useful to ask the supplier a few direct questions:

Question Why It Helps
Is the silk raw or degummed? Helps understand handle and finish
Is the yarn reeled or spun? Helps understand smoothness and irregularity
Is it filature silk? Indicates continuous reeled silk quality
Is the yarn twisted? Helps understand strength and fabric behaviour
Is it single, double or folded yarn? Helps understand body and durability
Is it used in warp or weft? Helps understand performance in weaving
What is the twist level? Helps identify chiffon, crepe or organzine type yarns

A fabric name alone is not enough.

For example, two fabrics may both be called “silk fabric”, but one may be made from raw silk, another from katan, another from spun silk and another from synthetic filament.

The buyer should always ask for the yarn story behind the fabric.

Common Mistakes

Mistake 1: Treating Raw Silk as a Fabric Name Only

Raw silk is not only a market category. Technically, it refers to silk thread containing its natural gum.

Mistake 2: Confusing Bivoltine with a Fabric Type

Bivoltine refers to the silkworm race and cocoon production cycle. It is not a weave or fabric construction.

Mistake 3: Confusing Organzine with Organza

Organzine is a yarn. Organza is a fabric.

Mistake 4: Assuming All Silk Yarns Are Smooth

Silk yarns may be smooth, twisted, folded, raw, degummed, spun, waste-based or irregular. Each gives a different fabric character.

Mistake 5: Ignoring Warp and Weft Difference

Some yarns are especially suitable for warp because they have better strength and stability. Organzine is a good example.

Knowledge Nugget

A silk fabric does not begin at the loom.

It begins much earlier.

It begins with the silkworm race, the cocoon, the filament, the gum, the reeling method and the yarn twist.

That is why a good textile person reads silk backwards:

Fabric → weave → yarn → filament → cocoon

The more we understand this chain, the more clearly we understand the fabric.

Quick Recap

In this part, we studied five important silk yarn-related terms:

Term One-line Meaning
Raw silk Silk thread containing natural gum or sericin
Bivoltine silk Silk from silkworm races with two generations in a year
China silk Lightweight silk fabric or superior white raw silk yarn
Katan Twisted filature silk
Organzine Folded and twisted silk yarn mainly used as warp

Main lesson: Silk yarn terms are not just definitions. They explain the behaviour of the final fabric.

Reflection Questions

  1. Why does raw silk feel firmer than degummed silk?
  2. Why is organzine suitable for warp?
  3. How is katan different from ordinary untwisted silk?
  4. Why should China silk be understood from context?
  5. Why is bivoltine silk not a fabric-construction term?

Final Words

Silk fabrics become easier to understand when we understand silk yarns.

Raw silk explains gum and body.

Katan explains twist and strength.

Organzine explains warp performance.

China silk reminds us that one term may have more than one meaning.

Bivoltine silk takes us even further back, to the silkworm race and cocoon source.

So before asking, “What silk fabric is this?”, we should ask:

What silk yarn is this fabric made from?

That question changes our understanding completely.

In the next part, we will move from yarn to twist-based sheer fabrics and understand chiffon, chiffon twist, georgette and crepe-georgette yarns.

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How to cite this article:
Goyal, P. Silk Fabric Terms Explained — Part 2: Understanding Silk Yarns. My Textile Notes. Available at: http://mytextilenotes.blogspot.com/2026/05/silk-fabric-terms-explained-part-2.html
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