Interfacing

Interfacing is a layer of fabric placed between the outer fabric and the facing to stiffen, shape or support parts of a garment such as collars and cuffs.

Interfacing is hidden structure. It is sewn or fused to the inside of collars, cuffs, waistbands, button stands and lapels so they hold their shape. Traditional tailoring uses canvases of horsehair and wool stitched by hand; modern clothing mostly uses fusible interfacings bonded with heat.