Fabric Definitions — definitions of fabrics, cloths, laces and textile materials from Apparel Search
Rib knit is a double-knit fabric knitted in a vertical ridged pattern called ribbing, highly stretched in the crosswise direction, and rib fabric is often used in round necks and cuffs for certain types of T-shirts. Ribbing is notated by (number of knit stitches) x (number of purl stitches), so 1x1 ribbing alternates one knit stitch with one purl stitch, and ribbing has a strong tendency to contract laterally, the purl stitches receding and the knit stitches coming forward.
What is ribbed fabric? It is a knitted fabric with a rib pattern.
Rib knit is a double-knit fabric that knits the fabric in vertical ridged pattern called ribbing and highly stretched in crosswise direction. Rib fabric is often used in round necks and cuffs for certain types of T-shirts.
Ribbing is notated by (number of knit stitches) × (number of purl stitches). Thus, 1×1 ribbing has one knit stitch, followed by one purl stitch, followed by one knit stitch, and so on.
Ribbing has a strong tendency to contract laterally, forming small pleats in which the purl stitches recede and the knit stitches come forward. Thus, ribbing is often used for cuffs, sweater hems and, more generally, any edge that should be form-fitting. The elasticity depends on the number of knit/purl transitions; 1×1 ribbing is more elastic than 2×2 ribbing, etc. However, some cable patterns may "pull in" more than ribbing (i.e., have a smaller gauge); in such cases, a ribbed border may flare out instead of contracting.
In knitting, ribbing is a pattern in which vertical stripes of stockinette stitch alternate with vertical stripes of reverse stockinette stitch.
Rib requires two sets of needles operating in between each other so that wales of face stitches and wales of back stitches are knitted on each side of the fabric.
You may want to also learn about twill and corduroy.
In our women's cotton corduroy pants guide, you can also learn about the wale on fabric.
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Ribbing is the knitting pattern garments rely on wherever an edge must grip. Its geometry is simple: columns of stockinette — the smooth V-columns of plain knitting — alternate with columns of reverse stockinette, where the purl bumps face forward. Because the two stitch types sit at different depths, the fabric folds itself into fine vertical pleats without any sewing or elastic thread, and the pleats act like springs in the width direction. Stretch a ribbed cuff and the pleats flatten and widen; release it and they fold shut again. The fineness of the notation tunes the spring: 1x1 rib folds at every stitch and contracts the most, 2x2 rib forms broader, flatter ridges with somewhat less snap, and wider ribs read increasingly as a design texture rather than a fitting device. This is also why a ribbed border occasionally flares instead of contracting: where a neighboring cable pattern pulls in even harder than the rib, the rib is stretched wider than its natural state by comparison — contraction is relative to the fabric beside it.
In garment manufacture, rib is produced as a fabric in its own right — a double-knit with vertical ridges, knitted on two needle beds, sold by the roll and cut for the parts of garments that need its properties: the round necks and cuffs of T-shirts named in the definition, waistbands, sock tops, polo collars and the body of fitted sweaters. Its crosswise stretch is far greater than its lengthwise stretch, so pattern cutters orient the ridges to run around the wrist or neck, putting the spring where the opening must expand over a hand or head and then close. Rib fabric also serves as a design surface in its own right: a fully ribbed sweater or dress uses the vertical ridge lines to shape visually, the pleats opening over curves and closing at the waist. Compared with woven rib effects such as poplin's, the difference is mechanism — poplin's rib is a ridge of yarn sizes in a fixed woven grid, while knit ribbing's ridges are folds that move, which is why only the knitted version can fit a cuff.
The notation counts the stitches in each stripe: 1x1 ribbing has one knit stitch, then one purl stitch, repeating; 2x2 has two knit stitches followed by two purl stitches. The elasticity depends on the number of knit/purl transitions — 1x1 ribbing, with a transition at every stitch, is more elastic than 2x2 ribbing.
The alternating stripes are not flat: knit stitches come forward and purl stitches recede, so the fabric pleats itself and contracts laterally. That built-in contraction is exactly why ribbing is used for cuffs, sweater hems and any edge that should be form-fitting — the edge hugs the wrist, waist or neck and recovers after stretching.
Rib requires two sets of needles operating in between each other, so that wales of face stitches and wales of back stitches are knitted on each side of the fabric. That intermeshed two-bed structure is what makes rib a double-knit fabric rather than a single jersey.