Why Do Jeans Get Weird Ripples After Washing?

You toss your favorite pair of jeans in the wash, predicting them to come out clean and fresh. But when you pull them from the dryer, you notice strange ripples or wavy lines running down the fabric — especially near the seams or thighs. What happened? Are they ruined?

Don’t worry, this is a popular issue. Here’s what causes those weird ripples in jeans after washing, and what you can do to prevent them.

1. Fabric Shrinkage and Uneven Drying

The most popular reason jeans develop ripples after washing is uneven shrinkage. Denim is usually made from 100% cotton or a cotton blend, and cotton fibers naturally shrink when exposed to heat and moisture. If parts of the jeans shrink more than others — especially around thick seams or reinforced areas — the fabric starts to pucker or ripple.

This is more likely to occur when jeans are washed in hot water or dried on high heat. The heat causes the cotton fibers to tighten up, and if the fabric doesn’t shrink evenly, you’ll see wavy patterns or twisted legs.

2. Tension During Manufacturing

Another reason for post-wash ripples is related to how the denim is made. During the weaving and sewing process, different parts of the jeans are stitched under tension. If the tension isn’t evenly distributed, the fabric may look smooth at first but once washed, those areas begin to shift and buckle, creating ripples or twisting.

Cheaper jeans or those made with less attention to construction may be more prone to this issue. Even expensive jeans, though, can develop ripples if they’re made with stretch denim or inconsistent stitching.

3. Stretch Denim and Elastane Issues

For comfort and stretch, many contemporary jeans contain elastane, often known as spandex. Stretch denim is incredibly flexible, but after several washings, it may start to ripple. The outer layer may warp or pull unevenly because the synthetic fibers may shrink or degrade differently than the cotton. 

 

 

Stretch is a crucial component of thin jeans and jeggings, so this is particularly apparent. After washing and drying, the variation in fiber behavior becomes increasingly noticeable over time.