Puckering

Definition and Position in the Process

Puckering is a phenomenon in which the textile gathers along the seam after sewing, causing ripples and wrinkles to appear. It is also called sewing shrinkage or seam wrinkling, and it affects not only appearance quality but also seam stretch and how the garment looks when worn.

It occurs during the sewing process after cutting, and may become noticeable during intermediate finishing such as pressing or steaming, or during final finishing. In some cases, it is first noticed after washing, product washing, or product dyeing, when differences in shrinkage between the material and the sewing thread appear.

Main Causes

The cause is not limited to just one factor. If the sewing thread tension is too strong, the thread pulls the textile together and causes sewing shrinkage. It is affected by machine conditions such as upper and lower thread tension balance, feed amount, presser pressure, and sewing speed.

Thin materials, soft textiles, stretchy knits, and low-density textiles tend to show deformation during sewing on the surface. In areas where the outer fabric is combined with interlining, lining, or tape, attention is also needed to differences in thickness, stretch, and shrinkage.

It can also occur when the shrinkage characteristics of the sewing thread and textile do not match, or when cutting and sewing are done with the grain line shifted. Textile wrinkles, skewing, and changes in hand caused by processing should be distinguished from puckering caused by the seam.

• Excessive sewing thread tension or imbalance between upper and lower threads
• Stretching or shifting of the textile by the feed dogs and presser foot
• Differences in shrinkage among sewing thread, textile, and accessories
• Mismatch between needle, thread count, stitch density, and material
• Dimensional changes after pressing, washing, or product processing

How to Proceed and Practical Points

Before mass production, conduct sewing tests using the actual outer fabric, accessories, and sewing thread. It is important to check areas that easily affect appearance, such as sewing direction, stitch type, overlapped sections, curves, and pocket openings.

The basic countermeasure is not to make the thread tension stronger than necessary. Then select a needle and sewing thread suitable for the textile, and adjust presser pressure, feed conditions, and sewing speed. Areas that stretch easily should be stabilized with stretch-restricting tape or similar materials, according to the specification.

Test samples should not be judged only immediately after sewing; they should also be checked after the specified finishing and washing tests. Record the corrections in the specification sheet together with the thread, needle, machine conditions, and pressing conditions used, and standardize the conditions within the factory.

Points to Note for Ordering and Quality Checks

When placing an order, clearly define unacceptable areas and appearance standards in the specification sheet or with a sample. Share the key inspection points for seams that are visible on the front side of the product, such as the collar, front placket, sleeve attachment, side seams, pocket openings, and zipper attachment.

During inspection, check not only by placing the item on a flat surface, but also while hanging on a hanger and in a worn state. Since ripples may look more pronounced depending on the lighting and viewing angle, judge in multiple conditions. Attention is also required for material differences and variations in sewing conditions from lot to lot.

Puckering is different from intentional wrinkled finishes or the natural surface texture of the textile. However, because the acceptable range depends on the material's hand, it is practically important to agree on approval samples before mass production.

Frequently Asked Questions