Rib Attachment

Definition and Overview

Rib attachment is an on-the-floor term for a specification in which rib knit fabric is attached to edge areas such as the body and sleeves, or it refers to the attached rib section itself. By using stretch and recovery, it provides garment fit, mobility, and shape retention at the edges.

It is distinguished from “rib knit” as a material name or knit fabric name. Rib knit is a knit structure with alternating knit and purl stitches, whereas rib attachment is a specification that indicates where and how that fabric is used in the product.

Knit Method and Structure

Rib knit with raised ribs formed by the arrangement of knit and purl stitches is often used for attached parts. The fineness of the ribs, knitting density, and yarn thickness affect appearance, thickness, tightness, and recovery.

Because rib stretches easily in the crosswise direction, it is generally cut or knitted shorter than the circumference of the cuff or hem and then sewn on while evenly stretched. Properly setting this difference helps prevent looseness and excessive tightness.

In addition to rib knit, plain stitch, TERECO Rib Fabric, and ladder stitch fabrics are also used as attachments. Rib with elastic yarn knitted in is chosen for specifications that require greater stability at the opening.

• Rib structure: The arrangement of knit and purl stitches changes how the ribs look and how they stretch.
• Gauge: An indicator of machine needle fineness; texture and thickness are not determined by the number alone.
• Number of elastics: Refers to the number of elastic yarn insertions, which affects holding power and firmness.

How the Specification Is Written

In a specification sheet, list the rib type, color, gauge, knit structure, whether elastic is included and how much, finished width, and the part where it is attached. Gauge is a machine specification and does not directly indicate the finished rib width or thickness, so samples and actual goods should also be checked.

“Rib attachment dimension” generally refers to the visible dimension of the rib after it is attached to the product, or the finished dimension. However, it may also refer to the cutting dimension or knitting dimension before seam allowance is included, so the reference point and treatment of seam allowance must be stated clearly.

For width, make clear whether it is the finished dimension laid flat or the visible width of the rib when folded in half. For the collar, specify whether the collar stand is included, and for cuffs and hems, indicate where to measure from the seam to prevent differences in interpretation by part.

Main Uses and Selection

Rib attachment is used for cuffs, hems, and collars on cut-and-sew items, sweatshirts, blousons, and similar products. At cuffs and hems, it helps block wind while maintaining ease of movement, and at collars, it follows the neck line to make dressing and undressing easier.

When selecting, check thickness relative to the main fabric, amount of stretch, recovery, color difference, and shrinkage after washing. If the rib is too weak compared with the body fabric, the opening can become loose easily; if it is too strong, it can cause tightness during wear and seam waviness.

• Cuffs: Check how well they fit the wrist and how they return when the sleeves are rolled up.
• Hem: Check the amount of narrowing relative to the garment silhouette and how the length appears.
• Collar: Check both the stretch needed for the head to pass through and the ability of the neckline to return after wear.

Sewing Notes

The circumference difference between the rib and the main body should be distributed evenly using notches during sewing. If the stretch amount is concentrated in one area, it can easily cause gathered slack, seam waviness, and left-right imbalance. When joining in a loop, also check the seam thickness and position.

During sewing, it is important not to pull only the rib excessively, but to feed it steadily together with the main fabric. If the needle, thread, feed, or presser foot pressure does not suit the fabric, skipped stitches, thread breakage, or insufficient seam stretch may occur.

For products that are washed or garment-washed, confirm the difference in shrinkage rate between the rib and the main fabric in advance. In particular, because the neckline, cuffs, and hems are used frequently, also evaluate twisting, stretching, and seam puckering after washing.

Frequently Asked Questions