Skipped Stitches

Definition and Overview

Skipped stitches are a phenomenon in which, at points where a seam should be formed continuously, the threads do not interlock properly in part, leaving only needle holes or causing missing stitches. They occur in lockstitch, chainstitch, overlock, and similar seams, and affect both appearance and seam strength.

They may not be noticeable on the surface, but if the seam is pulled, the unformed section may open up. This is a defect in the sewing process and is distinguished from textile defects, which are weaving or knitting flaws in the textile itself.

Processes Where They Occur and Main Causes

Skipped stitches occur in the sewing process when the cut pieces are sewn together. If the motion from the needle penetrating the textile to the hook or button loop reliably catching the thread loop becomes irregular, a stitch may not be formed.

There is not always a single cause. Check comprehensively for the textile's elasticity, thickness and step differences, thread type and thickness, needle type, size, and wear, thread tension, and the machine's timing and feed. In particular, knit fabrics that stretch easily and multi-layer areas are more affected by conditions.

• Needle tip wear, bending, or an unsuitable needle type or size
• Improper threading or tension of the upper thread and lower thread, or button loop thread
• Thread thickness, stretch, or slipperiness not suited to the textile
• Poor feeding or pulling of the textile at thick intersections, step differences, or stretch sections
• Improper machine adjustment, such as the positional relationship between the hook or button loop and the needle

Procedure and Practical Points

When it occurs, first record the sewing location, sewing direction, front and back of the textile, needle, thread, and machine type, then narrow down the conditions for reproduction.

If it does not improve, review the needle type and size, thread combination, presser foot pressure, and feed settings. For stretch materials, it is also important to feed the fabric without forcing it to stretch. Before mass production, check not only straight sections but also step sections and curved sections in sample sewing.

Points to Note for Ordering and Quality Control

When placing an order, share the textile to be used, sewing location, sewing specifications, planned thread and needle, and visually important areas in the specification sheet. If the material or specifications change, confirm sewability with trial sewing under conditions close to mass production, and identify in advance the conditions under which skipped stitches are likely to occur.

During inspection, do not just trace the seam line while laying the product flat; lightly open the seam and check for unformed sections. Whether they are acceptable and how they should be repaired depends on the product's applications, seam location, and sewing specifications, so judgment should be made according to inspection standards agreed on in advance.

Differences from Similar Terms

Thread breakage is a phenomenon in which the thread itself breaks during sewing or use. Skipped stitches, by contrast, refer to a state in which the thread loop cannot be caught and the stitch is not formed, even though the thread has not broken. Both may occur at the same time.

Puckering is an appearance defect involving waviness or wrinkles around the seam line. Skipped stitches are a defect related to missing stitches, and should be treated as a separate item when identifying the cause.

Frequently Asked Questions