Those curved lines are moiré. It happens when a fabric’s fine repeating pattern interacts with the camera sensor, creating false wavy or vibrating-looking lines.

For post-processing, you can reduce it with software tools made for moiré removal. Lightroom includes a built-in moiré reduction tool, and Photoshop also has workflows and tutorials for reducing the effect.

To help avoid moiré in future shoots, try small changes during capture, such as adjusting distance, angle, or framing so the fabric pattern doesn’t line up with the sensor in the same way.