What is curtain interlining?

Curtain Interlining: The Invisible Game-Changer

1. Core Purpose
Thermal Insulation: Traps air between window and room, blocking drafts and reducing heat loss in winter.
Light Control: Adds density to block light leaks around edges and seams, enhancing blackout effects.
Structural Enhancement: Gives curtains weight, helping them hang with defined pleats and fluid folds instead of clinging flat.

2. Material Types

3. How It's Applied
"Sandwich" Construction: Interlining sits between the decorative face fabric and the backing lining. Never fused—always loose-laid or basted.
Pleating Secret: Cut 3-4cm wider than face fabric to allow "ease," creating fuller, deeper pleats that hold shape.

4. Functional vs. Decorative Use
Functional (Essential For):
North-facing rooms (cold drafts)
Bedrooms (light-sensitive sleepers)
Street-facing windows (noise/traffic)
Decorative (Skip If):
Sheer curtains (defeats airy effect)
Café-style short curtains (no insulation needed)

5. Industry Insider Tips
Color Matters: Use white/cream interlining behind light fabrics—dark types shadow through linen or silk.
Moisture Trap Fix: In humid climates, avoid cotton interlining—opt for synthetic nonwoven to prevent mildew between layers.
Pleat Preservation: "Crush" interlining by hand before sewing—pre-shrinks it and ensures pleats reform after cleaning.

6. Common Mistakes
Fusing interlining to fabric: Creates cardboard-stiff curtains that hang like boards.
Skipping edge overlock: Unfinished edges puff out between curtain layers after washing.
Using upholstery interlining: Too stiff—curtains won't "break" at the hem (drapes pool, don't flow).

7. When to Upgrade
Heavy Velvets/Damasks: Use bump interlining (extra-loft) for opulent "theater curtain" weight.
Historic Homes: Horsehair woven interlining—only choice for conservation-grade drapery.