Movement during washing adds to the problem. Jeans can twist, stretch, and bunch up—particularly in an overloaded machine—creating uneven tension that leads to visible waves or puckering.
Water absorption is another factor. Denim doesn’t soak evenly, and stretch fabrics may expand more in certain areas. As they dry, these sections shrink at different rates, leaving a distorted look.
Crowding the washer or dryer makes things worse. Jeans can dry while twisted or folded, setting unwanted creases and ripples into the fabric.
To prevent this, wash jeans in cold water and avoid high heat. Air drying is ideal, but if using a dryer, choose a low-heat setting and remove them while slightly damp.
Turning jeans inside out, using a gentle cycle, and avoiding overloading the machine can help preserve their shape and keep them looking smooth longer.