Interlining is an invisible layer of fabric that is sandwiched between the visible parts of your curtains – the decorative main fabric that faces into your room and the lining that faces out the window. Typically made of cotton, interlining has a similar texture to cotton wool or a flannel blanket.
Benefits of interlined curtains
Insulation – interlined curtains are thicker than single-lined curtains, therefore they do a much better job of keeping your room warm. Windows are notorious cold spots, especially if you have sash windows or single glazing. Interlined curtains provide an extra barrier to prevent cold drafts blowing in and warm air seeping out.
Looks – the middle layer in interlined curtains means they are heavier than unlined curtains. This extra weight means they hang better, looking thick and sumptuous whether open or drawn. Interlining can also be used in Roman blinds, giving them a similar luxurious appearance.
How to line curtains
Making curtains with interlining is fairly straightforward. Start with your decorative fabric (the layer of the curtain that will face into the room). Lay it face up on a table and mark the position of the hemlines with pins. Turn it over so the fabric is face down on the table. Use weights to stop it sliding around. Place your interlining on top so the sides are level with the sides of the fabric, ensuring it is completely flat and smooth.
Fold back the interlining lengthways and interlock to the fabric every quarter width, half width, and then 10cm in from the side edges. Press the edges with the both interlining and fabric as one. Unfold then mitre the corners, slipstitching in place. Use herringbone stitch along the hemline. Once the interlining is secured, in place, the lining can then be attached by laying it face up on top and sewing in place.