Common Knit Fabrics

Common Knit Fabrics: A Practical Guide to Yarn Count, GSM and Fabric Structure

Knitted fabrics are among the most widely used fabrics in garments because they are comfortable, stretchable, flexible and suitable for body movement. T-shirts, polos, leggings, sweatshirts, thermals, innerwear, sportswear and many casual garments are made from different types of knit fabrics.

For a merchandiser, designer, buyer or textile student, it is not enough to know only the fabric name. One should also understand the relationship between yarn count, GSM, fabric structure, stretch, handle and end use.

Simple idea: In knit fabrics, yarns are converted into intermeshing loops. The shape, density and arrangement of these loops decide whether the fabric behaves like jersey, rib, interlock, pique, terry, fleece, waffle or thermal fabric.

1. What Makes Knit Fabrics Different from Woven Fabrics?

In woven fabrics, two sets of yarns — warp and weft — interlace with each other. In knitted fabrics, yarns form loops. These loops give knitted fabrics their natural stretch and flexibility.

The two important loop directions in weft-knitted fabrics are:

• Wales: vertical columns of loops.
• Courses: horizontal rows of loops.

The density of knitted fabric is often understood through courses per inch and wales per inch. A useful relationship is:

\[ \text{Stitch Density} = \text{Courses per inch} \times \text{Wales per inch} \]

Higher stitch density generally gives a more compact, stable and better-quality fabric, although it may reduce openness, air permeability and softness depending on yarn and finish.

2. GSM and Yarn Count in Knit Fabrics

GSM means grams per square metre. It tells us the weight of the fabric. In general, for the same fabric structure, a coarser yarn count gives a heavier GSM, and a finer yarn count gives a lighter GSM.

For example, in cotton single jersey:

• 40s cotton yarn may give a light fabric around 100–120 GSM.
• 30s cotton yarn may give a medium fabric around 140–155 GSM.
• 20s cotton yarn may give a heavier fabric around 180–200 GSM.
• 16s cotton yarn may give a heavy fabric around 230–250 GSM.

Technical point: GSM is not controlled by yarn count alone. It is also affected by loop length, machine gauge, stitch density, finishing, relaxation, compacting and shrinkage control.

3. Common Knit Fabrics and Their Uses

Fabric Type	Typical Structure	General Handle / Behaviour	Common Uses
Single Jersey	Single-knit structure with face and back clearly different	Light, flexible, curls at edges, good drape	T-shirts, tops, nightwear, casualwear
Slub Jersey	Jersey made with slub yarn	Irregular texture, casual look, uneven thick-thin effect	Fashion T-shirts, casual tops
Cotton/Spandex Jersey	Jersey with elastane/spandex plating	Stretchable, better recovery, close fit	Leggings, fitted tops, sportswear, innerwear
Pique	Textured knit with small raised cellular or honeycomb effect	More structured than jersey, breathable, slightly firm	Polo shirts, sports-casual garments
1x1 Rib	Alternate knit and purl wales	High widthwise stretch and recovery	Neck ribs, cuffs, waistbands, fitted garments
2x2 Rib	Two knit wales followed by two purl wales	Bulkier and more pronounced rib effect	Cuffs, trims, sweaters, body-fit garments
Interlock	Double-knit structure derived from rib	Smooth on both sides, stable, thicker, less curling	Premium T-shirts, babywear, innerwear, uniforms
Loop Back Terry	Back side has uncut loops	Absorbent, soft, heavier than jersey	Sweatshirts, joggers, hoodies, loungewear
Brushed Back Terry / Fleece	Terry back is brushed to raise fibres	Warm, soft, bulky, insulating	Winter sweatshirts, hoodies, tracksuits
French Terry	Looped back, usually smoother and lighter than fleece	Comfortable, absorbent, medium warmth	Premium casualwear, sweatshirts, athleisure
Waffle Knit	Raised square or honeycomb-like texture	Textured, absorbent, thermal pockets	Thermal tops, towels, robes, casualwear
Thermal Knit	Cellular structure designed to trap air	Warm, insulating, textured	Winter innerwear, base layers

4. Common GSM Ranges for Cotton Knit Fabrics

The following table gives broad industry-style reference ranges. Actual GSM may vary depending on machine settings, yarn quality, finishing and fabric relaxation.

Content	Yarn Count	Fabric Type	Approx. GSM Range
100% Cotton	40s Combed	Single Jersey	100–120
100% Cotton	36s Combed	Single Jersey	110–130
100% Cotton	30s Combed	Single Jersey	140–155
100% Cotton	26s Combed	Single Jersey	160–170
100% Cotton	24s Combed	Single Jersey	165–180
100% Cotton	20s Combed	Single Jersey	180–200
100% Cotton	18s Combed	Single Jersey	210–230
100% Cotton	16s Combed	Single Jersey	230–250
95/5 Cotton/Spandex	40s + 20D	Single Jersey	160–180
95/5 Cotton/Spandex	32s + 20D	Single Jersey	190–200
95/5 Cotton/Spandex	30s + 20D	Single Jersey	200–210
95/5 Cotton/Spandex	30s + 30D	Single Jersey	220–230
100% Cotton	30s Combed	Pique	180–190
100% Cotton	26s Combed	Pique	190–200
100% Cotton	24s Combed	Pique	200–220
100% Cotton	20s Combed	Pique	210–240
100% Cotton	18s Combed	Pique	240–250
100% Cotton	16s Combed	Pique	260–280
100% Cotton	40s Combed	1x1 Rib	140–160
100% Cotton	30s Combed	1x1 Rib	180–200
100% Cotton	24s Combed	1x1 Rib	220–240
100% Cotton	20s Combed	1x1 Rib	250–270
100% Cotton	16s Combed	1x1 Rib	300–340
100% Cotton	40s Combed	Interlock	180–200
100% Cotton	30s Combed	Interlock	220–240
100% Cotton	26s Combed	Interlock	240–260
100% Cotton	24s Combed	Interlock	270–280
100% Cotton	20s Combed	Interlock	300–320
100% Cotton	16s Combed	Interlock	330–350
100% Cotton	30s Combed	Loop Back Terry	180–200
100% Cotton	24s Combed	Loop Back Terry	220–230
100% Cotton	20s Combed	Loop Back Terry	240–260
100% Cotton	16s Combed	Loop Back Terry	280–290
95/5 Cotton/Spandex	30s	French Terry	240–260
80/20 Cotton/Poly	30s + 10s PC	3-End Fleece	300–340
80/20 Cotton/Poly	20s + 10s PC	2-End Fleece	260–300
100% Cotton	40s Combed	Waffle / Thermal	140–160
100% Cotton	30s Combed	Waffle / Thermal	180–200
100% Cotton	20s Combed	Waffle / Thermal	250–270
100% Cotton	16s Combed	Waffle / Thermal	300–340

5. How to Identify Jersey, Rib and Interlock Fabric

Single Jersey

Single jersey has a clear face and back. The face side shows vertical wales, while the back side shows a different loop appearance. It curls easily at the edges. When cut, it may curl towards the face or back depending on the direction of cut.

Rib

Rib fabrics show alternate face and reverse wales. They stretch strongly in the width direction. This is why rib fabrics are used for cuffs, collars, neckbands and waistbands. A 1x1 rib has one face wale and one reverse wale alternately. A 2x2 rib has two face wales and two reverse wales alternately.

Interlock

Interlock is a double-knit structure. It is usually smoother and more stable than single jersey. Both sides may look similar, and the fabric is thicker and less prone to curling. It is commonly used in babywear, innerwear, premium T-shirts and garments where better dimensional stability is required.

6. Pique Fabric

Pique is commonly used for polo shirts. It has a textured surface, often with a small honeycomb or cellular appearance. Compared with single jersey, pique usually feels more structured and slightly thicker. It allows better air circulation because of its textured construction.

A cotton pique polo shirt is therefore often preferred where the garment needs more body than a regular T-shirt but should still remain comfortable.

7. Terry, French Terry and Fleece

Terry fabrics have looped yarns on the back side. These loops improve absorbency and bulk. In loop back terry, the loops remain visible. In brushed back terry or fleece, the loops are brushed to create a soft, raised, warm surface.

French terry generally has a smoother face and looped back. It is used in sweatshirts, joggers and athleisure garments where the fabric should be comfortable but not as bulky as heavy winter fleece.

8. Two-End Fleece and Three-End Fleece

Fleece fabrics may be produced as two-end or three-end constructions. In simple terms:

• Two-end fleece generally uses two yarn systems.
• Three-end fleece uses three yarn systems and can give better fabric body, stability and surface quality.

Three-end fleece is generally considered a higher-quality construction because it can offer a better face, more stable structure and better print surface. However, it is also more expensive to produce because it uses more yarn and often requires finer yarns to maintain the required GSM and stitch density.

9. Waffle and Thermal Knits

Waffle knit has a raised, square or honeycomb-like texture. The structure can trap air in small pockets, giving a warmer feel. Thermal knits are also designed to trap air and provide insulation. These fabrics are used in winter innerwear, base layers, robes and comfort garments.

10. Why Spandex Changes the GSM

When spandex is added to cotton knit fabrics, the GSM often increases. This is because elastane adds mass and also changes the compactness of the structure. A 95/5 cotton/spandex single jersey fabric made with 30s cotton and 20D or 30D spandex can be much heavier than a 100% cotton single jersey made from the same cotton count.

Spandex also improves:

• stretch,
• recovery,
• fit,
• shape retention,
• comfort in body-hugging garments.

11. Practical Selection Guide for Merchandisers and Designers

End Use	Suggested Fabric	Typical GSM Direction	Reason
Light summer T-shirt	Single Jersey	120–160 GSM	Light, soft, breathable
Premium T-shirt	Interlock or heavier Single Jersey	180–240 GSM	Better body and stability
Polo shirt	Pique	180–240 GSM	Textured, structured, breathable
Leggings / fitted tops	Cotton/Spandex Jersey or Rib	180–260 GSM	Stretch and recovery
Cuffs / neck ribs	1x1 or 2x2 Rib	As per garment requirement	High stretch and recovery
Sweatshirt	French Terry or Fleece	240–340 GSM	Bulk, comfort and warmth
Winter innerwear	Thermal / Waffle Knit	180–300 GSM	Air-trapping structure

12. Important Quality Points in Knit Fabrics

While selecting or approving a knit fabric, the following points should be checked:

• GSM: whether it matches the buyer’s specification.
• Width: whether usable width is suitable for marker planning.
• Shrinkage: both lengthwise and widthwise shrinkage after washing.
• Spirality: especially important in single jersey fabrics.
• Stretch and recovery: especially for spandex fabrics.
• Fabric appearance: slubs, holes, needle lines, barre, shade variation.
• Hand feel: softness, compactness, bulk and drape.
• Colour fastness: washing, rubbing, perspiration and light fastness.

Buyer’s checklist: A fabric name alone is not a sufficient specification. A proper knit fabric specification should mention fibre content, yarn count, fabric structure, GSM, width, shrinkage, colour, finishing, stretch requirement and end use.

13. Conclusion

Knit fabrics are simple to wear but technically rich to understand. A single jersey, rib, interlock, pique, terry or fleece fabric differs not only in appearance but also in structure, GSM, stretch, stability, cost and end use.

For practical textile work, the most important learning is this: fabric structure, yarn count and GSM must be studied together. A 30s yarn in single jersey, pique, rib or interlock will not give the same fabric weight or behaviour. The loop arrangement changes everything.

Therefore, whenever we select a knit fabric, we should not ask only, “What is the GSM?” We should ask:

• What is the fibre content?
• What is the yarn count?
• What is the knit structure?
• What is the stitch density?
• What is the end use?
• What kind of comfort, stretch and stability is required?

This is how a simple knit fabric table becomes a practical tool for garment development, costing, quality control and merchandising.

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How to cite this article:
Goyal, P. Common Knit Fabrics. My Textile Notes. Available at: http://mytextilenotes.blogspot.com/2010/04/common-knit-fabrics.html

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