Seam appearance

Seam puckering

A visible, wavy appearance on one or both sides of the seam is rarely desirable. Seam puckering is one of the most common processing problems in garment manufacturing. It can occur immediately after sewing, during ironing or pressing, or only after a short rest period along the seam or in certain areas of the seam. In practice, puckering is assessed visually and evaluated using a photo scale.

Seam marks

Seam marks visible on the outside are a well-known processing problem with fine fabrics. They occur when the seam allowances and/or sewing threads leave marks when the closing and serging seams are ironed.

Poor coordination of sewing thread and fabric

Sewing thread construction and ticket number often do not ideally emphasise the character of the fabrics and designs. If the sewing thread, needle size and fabric are not optimally matched, material damage can occur, for example, due to the use of needles that are too coarse. This damage usually only becomes visible after the first wash, when the fabric threads along the seam are brushed up.

Incorrect thread balance

As soon as the thread balance deviates from the ideal, an uneven seam pattern results, which is generally unacceptable for visible seams. The following illustration shows the appearance of a poor thread balance in a double lockstitch seam.

Poor colour matching

Unwanted colour differences in tone-on-tone stitching are easy to spot. This problem is less noticeable with contrasting coloured seams.

The following is important for achieving the optimum colour match between sewing thread and fabric:

• Colour matching, taking into account the metamerism effect
• Comparison of colour fastness between fabric, sewing thread and other materials
• Use of trained personnel with a keen sense of colour

Seam grinning

Even to the untrained eye, so-called grinning or protruding seams indicate that something is wrong with the processing. This mainly affects joining seams that are subject to heavy wear, such as seat seams. When a seam grins, the stitching between the two seam edges becomes visible.

When tension is applied across the direction of the seam, the sewing threads appear in the form of a ladder. Possible causes include poor thread balance, thread tension that is too loose or insufficient stitch density.
 

Conclusion

Seam appearance has a major impact on the perceived quality of a sewn product. A well-balanced combination of sewing thread, fabric, needle and sewing parameters helps prevent visible defects and ensures a clean, high-quality seam.