At high temperatures in the washer or dryer, Lycra begins to break down. When that happens, the denim fibers around it start to warp too. That’s why you end up with those strange ripples or puckers in random spots — not uniform shrinkage like with pure cotton.
Once Lycra loses its elasticity, there’s really no going back.
And it’s not just heat — washing jeans too often wears down the fibers over time. Most of us wash them far more than necessary. Experts actually recommend washing jeans much less frequently than you’d think, since overwashing shortens their lifespan and ruins that perfect fit.
2. The Washer Twists and Stretches the Fabric
Even if heat isn’t the issue, the way your jeans move inside the washer can cause problems. Think about it — your jeans aren’t just soaking gently in water. They’re being tossed, twisted, and stretched in every direction.
It gets even worse if you overload your washing machine — everything tangles up, and the fabric gets pulled unevenly.
Stretch denim is especially prone to this. When it’s wet and heavy, different areas dry under varying tension: some sections stay taut, others loosen. The result? Those annoying wavy ripples that make your jeans look like they’ve aged a decade overnight.
