What Fabric Is the Best for Thermal Insulation for Curtains?

What Fabric Is the Best for Thermal Insulation for Curtains?
Written By
Linda Erlam
Linda Erlam
Published: May 24, 2011
Updated: Nov 20, 2021
2 minute read

The type of lining used will affect the insulation value of the drapery, from little or no insulation to insulation that is as effective as hanging a quilt over the window.

Layering is the Key

The more layers of high-quality lining in a drapery, the better the insulation value. Custom-made drapery may have three or four linings that can, together with top treatments, rival the insulation factor of a 6-inch thick wall. Curtains can have removable linings attached at the ring or drapery pin, or additional drapery can be hung on separate rods to create a layered effect.

Blackout Lining

Blackout lining is a fabric that has been sprayed with acrylic or latex in two or three layers, on one side of a cotton or cotton blend fabric. This lining gives good insulating value and light does not pass through.

Flannel-backed Lining

One side of a cotton fabric is combed to create a flannelet-like surface. This fabric provides a medium insulation and allows some light to pass through. Good insulation is created by placing blackout lining between flannel-backed lining and the decorator fabric.

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French Blackout

Heavy black flannel is placed between the decorator fabric and regular lining to create a full blackout, highly insulating drapery treatment.

Additional Considerations

Some drapery fabric is not washable, and blackout lining is not dry-cleanable. To solve potential laundering problems, install the layers on separate curtain rods. Adding layers to existing curtains will increase the weight of the coverings considerably.

The Drip Cap

  • Curtains are fabric window treatments hung on a drapery rod by drapery pins or rings that open and close horizontally.
  • If lining is added, curtains become draperies.
  • Custom-made drapery may have three or four linings that can, together with top treatments, rival the insulation factor of a 6-inch thick wall.
  • Heavy black flannel is placed between the decorator fabric and regular lining to create a full blackout, highly insulating drapery treatment.

Photo Credits

Darrin Klimek/Digital Vision/Getty Images

Darrin Klimek/Digital Vision/Getty Images

Linda Erlam

Linda Erlam started writing educational manuals in 1979. She also writes a biweekly newspaper column, "Design Dilemmas," in the "Lakeshore News" and has been published in "Design and Drapery Pro" magazine. Erlam is a graduate of the…

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