Interlining is the piece of fabric that is sandwiched between the fabric and the back lining. It gives the curtain extra weight to help it drape more beautifully but it has other purposes including insulation, noise reduction, to reduce transparency, and to give the curtain a softer look and feel.

Why is interlining necessary?

Interlining is important in building shape into detail areas such as the front of coats, collars, lapels, cuffs and pocket flaps. It stabilises and reinforces areas subject to extra wear and stress like necklines, facings, patch pockets, waistbands, plackets and button holes.

Do I need interlining?

Interlining makes curtains look luxurious and drape elegantly. ... Lined and interlined curtains absorb more sound, and provide greater insulation from cold and draughts, than curtains with just lining. • Interlining is not just for curtains – Roman blinds also look great with added interlining.