Introduction
When a garment must move with the body, recover after wear, and still keep its shape, knit structure becomes a practical design concern for both apparel makers and learners. The way loops are formed affects durability, appearance, shrinkage, cover, and comfort in ways that are easy to notice in use, even before any technical testing is done. Knitted fabrics behave differently from woven goods because the looped construction allows more stretch and flexibility. That same structure can also create problems such as running, shape loss, or lower cover, depending on the yarn and knitting method, so the fabric has to be chosen with care. A small change in loop formation can shift several of these properties at once, which is why understanding the effects of knit structure on fabric performance is important when selecting and designing knitted fabrics.
Knitted Fabric Durability
Stretch and Recovery
Strength of knitted fabrics is considered to be less critical for durability than it is in woven goods. Knitted fabrics are easily stretched to accommodate changes of shape as a result of stresses imposed in wear and care, and this gives the structure useful give in everyday use. When knits are made from resilient fibers and yarns, the ability to stretch and recover from stretching will be improved, which helps the fabric respond better to repeated movement. In comparison to knitted fabrics, woven fabrics are generally firmer and have less elongation, so they hold their shape with less movement and less visible change.
In knits the loops in the structure can be deformed horizontally or vertically, increasing the stretch in both directions. But as noted earlier, variations in knitting techniques can increase or reduce extensibility of knitted fabrics, which is why construction matters so much when performance is being judged. Double-knit fabrics and warp-knit fabrics are usually less extensible than single-knit fabrics, and that difference is often easy to feel once the fabric is placed under tension.
Runs in Weft Knits
A major problem in the durability of knits is the runs that can develop in weft knits when one of the loops is broken. If stronger fibers and yarns are used in these knits, they will be less likely to run, which makes the fabric more dependable in wear and care. That balance between stretch and recovery on one hand, and loop stability on the other, is one of the first things people notice when a knit is used repeatedly.
Knitted Fabric Appearance
Shearing and Drape
The ability of a fabric to shear easily is an important factor in the appearance of textiles, especially when the fabric is expected to drape cleanly or maintain a smooth surface. In general, because of the ways in which yarns are combined, woven fabrics shear more easily than do knitted fabrics, so they usually respond in a more fluid way when shaped. Knitted fabrics have good flexibility and are easily extended, which gives them a very different visual behavior from woven goods and often a softer line in use. Warp knits do not shear as easily as weft knits, so they behave differently when the cloth is shaped on the body or arranged in the garment.
These qualities must be taken into account by designers, although they may not be aware of the technical terminology used to describe the fabric properties. For example, a warp-knit tricot fabric, which resists shearing, would not be the best choice for a bias-cut garment in which the intention is to take advantage of high shearing. Instead, the designer would be likely to use a soft, gathered construction where the high flexibility of the fabric would work to good advantage, while most of the draping would fall in the vertical direction of the fabric. That is a practical point that can change the final look of a garment even when the fabric itself seems simple.
Wrinkle Resistance and Shrinkage
In general, knits wrinkle less than do other fabrics. This is because loosely constructed fabrics allow more fiber redistribution and motion, which helps the surface relax. However, knitted fabrics, because of their greater extensibility, are more likely to lose their shape in laundering, and that can affect their finished appearance. The stresses applied in knitting distort the shapes of the loops rather than just stretching the yarns as in weaving. On relaxation, the loops broaden, shrinking the fabric length and increasing the width, so the fabric changes in two directions at once.
As with woven fabrics, the tighter the structure, the higher the shrinkage until the structure becomes so tight that further shrinkage is not possible. Such fabrics may, however, buckle, which shows how closely structure and stability are linked in this fabric class. This is one of the reasons knitted fabrics often need careful handling during laundering and finishing, and it also demonstrates the effects of knit structure on fabric performance during use and care.
Fabric Cover and Porosity
Knitted fabrics tend to have lower cover than do woven fabrics, with weft knits having substantially more porous structures than warp knits unless the fabric is deliberately made to have an open, lacy construction, as in some Raschel knits. Use of thinner or thicker yarns can increase the cover of knitted fabrics, giving the surface a fuller look when that is needed for the final fabric. In appearance terms, this means that knit structure affects not only drape and movement, but also how solid or open the cloth seems to the eye.
Knitted Fabric Comfort
Air and Warmth
Knits usually entrap more air than do woven fabrics, although the tightness of the knit is a factor as well, so the result is not the same in every construction. Pile or napped knit constructions are especially good for cold weather because the yarns or fibers perpendicular to the surface provide numerous spaces for dead air, and those spaces help the fabric hold warmth. This effect is maximized if such fabrics are worn with the napped or pile surface next to the body or if they are covered with another layer, which helps keep that air in place. For colder conditions, that trapped air is often the feature that matters most.
Softness and Hand Feel
The flexibility of knits contributes to a feeling of fabric softness, and that softness is part of the comfort people notice first. Fibers and yarns used can enhance or reduce the smoothness of knitted fabrics, so material choice still matters in the final hand of the cloth. In practice, comfort depends on both the knit construction and the way the fabric is made, and the two work together rather than acting alone. This is one reason knit fabrics can feel more forgiving against the body than firmer textile structures.
Conclusion
Taken together, these properties show that knit structure has direct effects on fabric performance in wear and care. Stretch, recovery, shearing behavior, shrinkage, cover, and air entrapment all change the way a knit looks and feels. Weft knits, warp knits, single-knit, double-knit, and tricot constructions each bring different strengths and limits, so each one must be viewed on its own terms. When these differences are understood clearly, knit fabrics can be matched more thoughtfully to the needs of the garment and the way it will be used. That understanding will continue to guide better choices in fabric selection and garment design.
Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. Mr. Kiron is working as a textile consultant in several local and international companies. He is also a contributor to Wikipedia.
