Tension puckering

Troubleshooting and sewing defects
Seam puckering caused mainly by excessive or unbalanced thread tension.
Also known as
Thread-tension puckering
Not to be confused with Check tension after ruling out feed and shrinkage effects.
Translations
DE Spannungskräuseln
FR Fronçage dû à la tension
ES Fruncido por tensión
IT Arricciatura da tensione
CN 张力起皱
VN Nhăn do sức căng