Interfacing is mainly used in sewing to add what?

Interfacing is primarily utilized in sewing to provide strength to fabrics, especially in areas that require reinforcement. This is critical for elements such as collars, cuffs, button plackets, and waistbands, where additional support is necessary to maintain the garment's shape and durability.

By applying interfacing, you improve the structure of the fabric, helping it withstand wear and tear while maintaining a polished appearance. This added strength ensures that the garment retains its intended form and functionality, especially in high-stress areas. While interfacing can also add some weight and change texture, its main purpose is to enhance the strength and stability of the sewn product.