Chain Stitch
A chain stitch is a stitch formed by continuously interlacing loops of thread with a looper, used for stretch-friendly sewing and for joining the hems and side seams of cut-and-sew knitwear.
Definition and Overview
Chain stitch is a sewing method that continuously interlaces the needle thread and button loop thread, or loops of multiple threads. Because the stitches appear linked like a chain, it is also called a chain stitch. There are several types depending on the stitch structure and the number of needles and button loops used.
In general, it follows stretch well and is suitable for sewing knitwear and stretch fabrics. On the other hand, if the thread end at the finish comes undone, it may unravel continuously, so it is important to define the finishing method in the sewing specifications.
Position in Product Development
Chain stitch is used in sewing processes after cutting, such as joining hardware together, hemming, and attaching belt loops. Whether to adopt it in the process is decided based on the fabric's stretch, the force applied during wear, the appearance required on the front and back, and whether there is a washing process in later steps.
In cut-and-sew products, it is often used in forms that simultaneously finish the seam allowance edge and join the pieces, or to secure the hem. In denim and similar products, it is also sometimes used to create a continuous stitch appearance on the front side.
Specification Decisions and Process
At the planning and pattern stage, indicate in the specification sheet where chain stitch will be used, the seam allowance width, the stitch appearance, thread color, and thread tension. Depending on fabric thickness and stretch direction, stitch breakage called popping, seam shrinkage, and waviness may occur, so sewing tests should be performed on actual fabric before mass production.
When giving instructions to the sewing factory, do not simply say "chain stitch"; share the machine type to be used, number of needles, front and back stitch appearance, whether backstitching is allowed, and even the thread-end finishing position. For products that undergo washing, also check the post-process stitch appearance and shrinkage.
- Check the stretch direction and sewing direction.
- Specify whether the seam allowance edge is overlocked.
- Confirm the stitch pitch and thread color with samples.
- Decide how to prevent fraying and finish the thread ends at the edges.
Ordering and Quality Considerations
When placing an order, attaching photos that show the front and back of the stitching and actual samples, in addition to the sewing specification sheet, helps reduce misunderstandings. Especially when the stitch is to be shown as a design feature, confirm the thread thickness, color difference, stitch width, and stitch straightness against approved samples.
During inspection, check for skipped stitches, thread breakage, dropped stitches, seam shrinkage, and puckering, which is wrinkling around the stitch area. For stretch fabrics, also evaluate whether the stitching breaks during wear or pulling, and whether the stitch stretches too much and does not return.
Differences from Similar Terms
Lockstitch is generally a stitch formed by interlacing the upper and lower threads inside the fabric, and its thread interlocking method differs from chain stitch. Lockstitch is less likely to unravel, while chain stitch has the characteristic of being easier to follow stretch depending on the specification.
Overlock is a sewing method that mainly wraps the fabric edge to prevent fraying. Chain stitch and overlock are sometimes used together, but their purpose, the machine used, and the front and back appearance of the stitch are not the same.
Frequently Asked Questions
Can chain stitch be used on fabrics other than knitwear?
Yes. It is also used on denim and woven fabric, taking into account the decorative effect of the stitching, the appearance after washing, and how well it follows movement. However, because the appropriate thread, needle, and sewing conditions differ depending on the fabric thickness and density, trial sewing before mass production is necessary.
Why is chain stitch easy to unravel?
Because chain stitch has a structure in which thread loops are continuously linked, if the thread end at the finish comes loose or breaks, it may unravel in sequence. Specify backstitching at the end, thread finishing, and overlaps with other stitches in the specifications, and confirm them on the finished product.
