Cheap mousepads curl. Humidity makes it worse.

Yes.

That thin rubber base is the problem. Cheap mousepads use low-quality rubber that doesn’t hold its shape, especially when humidity makes it expand and contract unevenly. The edges lift, and once they start curling, they never flatten out properly.

If you live in a humid climate, it gets worse faster. The rubber absorbs moisture, swells, then dries and shrinks, pulling the fabric edge up. You can try ironing it on low heat with a towel, or putting heavy books on it overnight, but that’s a temporary fix.

Better to spend a few extra bucks on a mousepad with a stiffer base—something with a thicker rubber or a textured hard surface. Or just accept that a $5 mousepad is disposable and replace it every few months.