Soft circuits (also called e-textiles) are electrical circuits made with flexible, fabric-friendly materials such as conductive thread and fabrics instead of traditional rigid wires. In a soft circuit, electricity flows along stitches sewn into felt or cloth to power LEDs, sensors, switches, and other small electronic components. They can appear in wearable accessories, art, costumes — any textile that integrates lights and electronics without soldering.

Conductive thread behaves much like ordinary sewing thread but carries an electrical current between components like a battery, LEDs, and switches. This lets makers embed functioning circuits directly into fabric designs.