Thursday, 1 April 2010

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% Cotton40s CombedSingle Jersey100–120
100% Cotton36s CombedSingle Jersey110–130
100% Cotton30s CombedSingle Jersey140–155
100% Cotton26s CombedSingle Jersey160–170
100% Cotton24s CombedSingle Jersey165–180
100% Cotton20s CombedSingle Jersey180–200
100% Cotton18s CombedSingle Jersey210–230
100% Cotton16s CombedSingle Jersey230–250
95/5 Cotton/Spandex40s + 20DSingle Jersey160–180
95/5 Cotton/Spandex32s + 20DSingle Jersey190–200
95/5 Cotton/Spandex30s + 20DSingle Jersey200–210
95/5 Cotton/Spandex30s + 30DSingle Jersey220–230
100% Cotton30s CombedPique180–190
100% Cotton26s CombedPique190–200
100% Cotton24s CombedPique200–220
100% Cotton20s CombedPique210–240
100% Cotton18s CombedPique240–250
100% Cotton16s CombedPique260–280
100% Cotton40s Combed1x1 Rib140–160
100% Cotton30s Combed1x1 Rib180–200
100% Cotton24s Combed1x1 Rib220–240
100% Cotton20s Combed1x1 Rib250–270
100% Cotton16s Combed1x1 Rib300–340
100% Cotton40s CombedInterlock180–200
100% Cotton30s CombedInterlock220–240
100% Cotton26s CombedInterlock240–260
100% Cotton24s CombedInterlock270–280
100% Cotton20s CombedInterlock300–320
100% Cotton16s CombedInterlock330–350
100% Cotton30s CombedLoop Back Terry180–200
100% Cotton24s CombedLoop Back Terry220–230
100% Cotton20s CombedLoop Back Terry240–260
100% Cotton16s CombedLoop Back Terry280–290
95/5 Cotton/Spandex30sFrench Terry240–260
80/20 Cotton/Poly30s + 10s PC3-End Fleece300–340
80/20 Cotton/Poly20s + 10s PC2-End Fleece260–300
100% Cotton40s CombedWaffle / Thermal140–160
100% Cotton30s CombedWaffle / Thermal180–200
100% Cotton20s CombedWaffle / Thermal250–270
100% Cotton16s CombedWaffle / Thermal300–340

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.

Friday, 26 March 2010

What is 100x120/92x80 Quality of Mull or Volile



100x120 quality of voile is a misnomer.Actually the count of the fabric is 64 x 80 or 64 x 90. The construction is the same as that of 92 x 80. It is a greige construction. Finished construction will be 104 x 80.

To understand it, there are various varieties available in the market. I am just giving a brief list in the decreasing order of qualities. In the first column I have given the popular name, in the second column I have given the reed and pick ( All Greige) corresponding to that quality.

100 x 120   92 x 104 ( A typical 100 x 120 quality has count of 56 x 90, Reed pick of 91 x 101)
100 x 120   92 x 88
100 x 120   92 x 80 ( A typical 100 x 120/92 x 80 has a count of 60 x 80 and Reed x pick of 90 x 76)
100 x 120   92 x 72
80 x 72       80 x 72 (A typical 80 x 72 quality has a count of 60 x 80 and Reed pick of 80 x 64)
100 x 100   76 x 68 ( A typical 100 x 100 quality has a count of 60 x 80 and reed pick of 76 x  60)
80 x 100     76 x 66
70 x 90       66 x 52 ( A typical 70 x 90 quality has a count of 60 x 90 and reed pick of 66 x 50)


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Saturday, 20 March 2010

Traditional Dabu Printing of India- Part 3



If Teal color needs to be obtained. Then indigo dyed fabric is first dipped into myrobalan solution and then treated with water of Iron. (Teal Background)


If Green color is desired then indigo dyed fabric is first treated with solution of Haldi and then treated with Alum. Please remember to dry in the night or dry upside down to get a green color.




To Get Red and Black as Motif, Green as background- Block 52 and 52A
a. The Fabric is first Dipped in Myrobalan

b. Then it is Printed With Red Process( Alum Paste) as explained earlier

c. Then it is Printed With Black Process (Iron Paste)

d. Then it is Washed and Boiled with Alizarin ( To get red on 1st Block)

e. Then it is Dyed in Indigo

f. Then it is Dipped in conc. solution of Pomegranate Chilka + Haldi ( For Green Back ground)( Green Process)

If the color is dark indigo is added

Remember if the indigo is not properly mixed then it will smear on the block color.

To Get a Brown Color in the Background

There are two methods
1.       In one method after the green process, the fabric is dipped in alum and then boiled in Alizarin ( Green +Redà Brown). The motif being resisted by Dabu.

2.       In other method the indigo dyed fabric is dipped in alum and then boiled in Alizarin ( Blue + Red-à Brown).

The two tones of brown are  different.

Green Motif (with Dabu)

To get Green Motif, in white process, some Haldi is added in the paste ( Means: kaali Mitti, Gum, Jaggery, Hydrate of Lime, Haldi)


Black Background with Hira Kashish ( Ferrous Sulphate – Hara thotha)

1.     Fabric is treated with Myrobalan and Dabu Done
2.     Hira Kashish is then mixed with water.
3.     The fabric will then turn to brown except dabu
4.       Then it is put to Alizarin boiling process it will turn to black
5.       Then it is washed properly.
To get a darker color, the fabric is again dipped in myrobalan after finishing. For example to get a darker brown fabric is dipped in Myrobalan.




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Friday, 19 March 2010

Traditional Dabu Printing of India- Part 2



How to Get Black Motif

Black color is obtained with the help of "iron water". To prepare iron water, Take 25 kg Iron Scrap+ water + Baajre ka aata + 2 kg ( Gud- Jaggery) . Close the lid from the top and keep it aside for 15 days.






Take out the iron, boil the water and then cook with Tamarind seed flour to prepare the iron paste for mixing with Iron. ( Black Process- NO Dabu)

To Apply it, first prepare the fabric using myrobalan. Then apply the paste to the fabric using printing blocks to give deep black color


Indigo Dyed Dabu



First of all fabric is desized just like the previous process.

Then it is treated with Castor oil in water to increase its absorbancy.


Then the dabu printing is done just like the earlier process.

After that the fabric is dried and then the fabric is put into indigo pot

The pot  is very old and the water is never changed. New indigo is kept on adding in it. It is generally 10 feet deep. Hydrate of Lime ( Ca(OH)2) is added time to time to keep the potency intact.

Generally there are two vats; one has 50% indigo and the other has 100% indigo. At a time two thaans are taken. The than is taken folded and gradually all the layers are exposed.
After that it is dried into the sun.

Another two dippings and dryings in the sun are done to get a dark tone.
If one wants to have one design with light and the other as a dark tone, the after printing the fabric is dipped into 50% indigo first and then dried.
After that dabu printing is done with the second design and the fabric is dipped twice into 100% indigo pot. The first type of dabu retains its whiteness, whereas the second type of dabu will become slightly less blue.  


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