Knit fabric is any textile made by interlocking loops of yarn, rather than weaving threads over and under each other. That loop structure is what gives knit fabrics their signature stretch and flexibility. Where woven fabrics like denim or canvas hold their shape rigidly, knits move with your body, which is why they dominate the world of t-shirts, activewear, underwear, and casual clothing.
How Knit Fabric Is Made
A single yarn (or set of yarns) is pulled through existing loops to create new loops, building row after row of interlocked stitches. The result is a fabric that stretches in at least one direction and often in all directions. This loop-based construction makes knits fundamentally three-dimensional: each stitch forms a small curve in space, which is why knit fabrics naturally curl at the edges when cut.
There are two broad methods of knitting. Weft knitting uses a single yarn feed and creates stitches that interlock the yarn with itself, moving across the fabric horizontally. This produces highly flexible, stretchy material and accounts for most of the knit fabric you encounter in everyday clothing. Warp knitting feeds many individual yarns simultaneously across the full width of the fabric. It creates a more stable structure and is common in swimwear linings, lace, and industrial textiles.
Common Types of Knit Fabric
Not all knits behave the same way. The stitch pattern determines how a fabric stretches, drapes, and holds up over time. Three types cover the vast majority of what you’ll find in stores and fabric shops.
Jersey Knit
Jersey is the most widely used knit fabric. It’s lightweight, soft, breathable, and stretches easily in both directions. One side shows smooth V-shaped stitches while the other has a slightly textured, loopy appearance. T-shirts, leggings, underwear, and lightweight dresses are almost always made from jersey. It works year-round because it layers well and comes in countless fiber options, from cotton to polyester blends.
Interlock Knit
Interlock is essentially two layers of jersey knitted together, creating a thicker, more stable fabric that looks smooth on both sides. It resists wrinkles better than single-layer jersey and holds its shape well over time. That extra weight makes it a popular choice for polo shirts, structured dresses, pants, and baby clothing. If you need a knit that feels substantial without being stiff, interlock is typically the answer.
Rib Knit
Rib knit has raised vertical ridges that give it a distinctive texture and exceptional elasticity. It snaps back into shape after stretching, which is why it’s the standard fabric for cuffs, waistbands, and neckline bands on everything from sweatshirts to jackets. On its own, rib knit works well for beanies, scarves, and fitted tops where you want a snug, body-hugging fit.
Knit vs. Woven: The Key Differences
The easiest way to tell a knit from a woven fabric is to pull it gently. Knits stretch noticeably, especially across the width. Woven fabrics resist that pull. Knits also tend to be softer, more breathable, and more forgiving in fit, which is why they’re preferred for anything worn close to the body. On the other hand, woven fabrics hold structured shapes better, which is why dress shirts, tailored trousers, and upholstery are almost always woven.
Knits also wrinkle less than most wovens. Interlock knit in particular has natural wrinkle resistance, making it a practical travel fabric. The tradeoff is that knits are more prone to pilling and can lose their shape if handled roughly.
Fiber Blends and Stretch
The yarn inside a knit determines how it feels, performs, and holds up. Cotton knits are soft and breathable but can shrink. Polyester knits dry faster and resist wrinkles. Many modern knits blend fibers to combine the best properties of each.
Activewear knits almost always include a small percentage of spandex (also called elastane) for recovery stretch, meaning the fabric snaps back instead of bagging out. Industry formulations vary, but you’ll commonly see blends ranging from 4% to 10% spandex. A fabric with 91% polyester and 9% spandex, for example, dries significantly faster than a nylon-spandex blend, which matters if you’re shopping for workout gear. Cotton-rich blends with around 5% elastane offer a softer hand feel while still providing enough stretch for comfortable movement.
How Knit Fabric Is Produced at Scale
Two types of machines produce nearly all commercial knit fabric. Circular knitting machines use a round needle bed to create seamless tubes of fabric at high speed. They can run up to 50 times faster than traditional methods, making them the go-to for large-volume production of basics like t-shirts and socks. Most of the jersey fabric in your wardrobe was knitted on a circular machine.
Flatbed knitting machines use straight needle beds and work more slowly, but they offer far more control over patterning and shaping. They can produce jersey, rib, interlock, and complex color patterns like fair isle and argyle. Fashion designers favor flatbed machines for smaller batches and custom garments where fit precision and unique design matter more than speed.
Why Knits Pill and How to Prevent It
Pilling happens when short or weak fibers work their way to the fabric’s surface and twist into tiny balls. Friction accelerates the process, which is why pills tend to form where your body rubs against the fabric: underarms, sides of the torso, and inner thighs.
The construction of the knit plays a major role. Tightly knitted fabrics trap fibers in place, so a dense jersey or Milano rib will pill far less than an open, airy gauge. Yarn quality matters too. Loosely spun, single-ply yarns feel wonderfully soft but release fibers much more easily. If you want a knit that resists pilling, look for tightly constructed fabrics made from tightly twisted or plied yarns.
Caring for Knit Garments
Knits keep their shape and softness longest when you treat them gently. For finer knits, especially wool or cashmere, hand washing in cold or lukewarm water with a gentle detergent is ideal. Submerge the garment without scrubbing, let it soak for a few minutes, then rinse without wringing. Roll it in a clean towel and press to remove excess water.
The single most important drying rule: never hang a wet knit. The weight of the water stretches the fabric and can permanently distort the shape, especially in the shoulders. Lay the garment flat on a dry surface in a well-ventilated area, away from direct sunlight. Skip the dryer entirely for anything you want to last. Sturdier cotton knits like t-shirts can handle a machine wash on a gentle cycle, but even those benefit from flat drying if you want to minimize shrinkage over time.
Sustainability in Knit Fabrics
Recycled polyester and bio-based fibers like lyocell are now used at commercial scale in knit fabric production, proving that sustainable options can match conventional fabrics in performance. The broader sustainable fabrics market is projected to reach over $41 billion in 2026 and could exceed $115 billion by 2035. Regeneratively farmed cotton, which improves soil health rather than depleting it, and hemp blends that require far less water are becoming more available in knit form. If sustainability matters to you, checking fiber content labels for recycled or plant-based materials is the simplest place to start.