Roman Blind Lining Guide: Blackout, Thermal & Standard Compared

Why Line a Roman Blind?

Unlined roman blinds are translucent — most woven fabrics allow some light through. Lining adds:

1. Privacy — opaque from outside during the day
2. Light control — reduced glare; blackout lining eliminates light entirely
3. Body — the blind hangs better and folds more crisply
4. Insulation — thermal lining reduces heat loss through the window
5. Fabric protection — lining shields the face fabric from direct UV which causes fading

Lining Types Compared

Bold = most common choice for DIY roman blinds.

Blackout Lining for Roman Blinds

Blackout lining is woven fabric with a foam or acrylic coating on the back that blocks light. Most blackout linings for roman blinds are “Blackout Sateen” — a soft, smooth fabric (cream or white) that sews easily and lies flat.

Important: Roman blinds with blackout lining do not achieve 100% blackout unless fitted inside a recess that fully encloses the blind edges. Light leaks around the sides and top if the blind is mounted outside the frame.

For true blackout (nurseries, shift workers):

• Use inside recess mount (blind edges enclosed by recess walls)
• Add blackout lining
• Consider a pelmet above to block the gap at the batten

Thermal Lining

Thermal lining has a layer of reflective material (usually aluminium-coated foam) that reflects heat back into the room. It is heavier than standard lining and works best on large windows.

Where it makes sense: North-facing rooms, large bay windows, rooms with old single-glazed sash windows. The thermal effect is most noticeable on drafty or cold windows.

Where it may not be worth it: Modern double or triple-glazed windows already have good thermal performance — the marginal gain from thermal lining is smaller.

Standard Lining

Plain cotton lining (also called sateen lining or curtain lining) is the most versatile and affordable option. It gives the blind body without significantly increasing weight, and the neutral colour (cream, ivory, white) protects the face fabric from UV without affecting the colour seen from outside.

When to choose standard lining: Any room where blackout is not required and the primary goal is improved drape and fabric protection.

Lining Cut Sizes

Lining is cut differently from face fabric. It fits inside the finished blind — no side hem allowance, and no top batten or bottom hem bulk.

Lining cut width  = finished blind width − 2 cm (0.8")
Lining cut length = finished drop + fold allowance + 2 cm (0.8")

Why no side hem allowance? The lining is stitched inside the face fabric side hems. If lining were cut the same width as face fabric, the side hems would be too thick to stitch cleanly. The complete face fabric cut size formula is in the Roman Blind Fabric Formula.

Why is lining shorter? The face fabric wraps over the batten (adding 5 cm) and forms a folded-double bottom hem (adding 10 cm). The lining doesn’t need these — it simply turns under 1 cm at top and bottom.

Example: 90 cm window, 120 cm drop, 4 folds, 12 cm fold depth (flat blind):

Face fabric cut: width 93 cm × length 231 cm
Lining cut:      width 86 cm × length 218 cm
                 (88 − 2 = 86;  120 + 96 + 2 = 218)

The Roman Blind Calculator calculates lining dimensions automatically when you check the lining option.

Lining Attachment Methods

Method 1: Lock stitch (loose attachment)

Lining is attached to face fabric with periodic lock stitches sewn down the length of the blind, not around the edges. The lining hangs independently inside the blind and moves with it. Gives a professional result, most forgiving of measurement differences.

Method 2: Slip stitch at edges

Lining is slip-stitched to the face fabric along the side and bottom edges. Faster than lock stitch but lining and face fabric must be cut very accurately — any mismatch shows as a pulling at the edges.

Method 3: Bag lining (machine sewn)

Face and lining are sewn right-sides-together around three edges, then turned through. The batten edge is left open. Fast and clean for beginners but the blind is thicker through the fold lines (both layers folded together).

Interlining

Interlining is a thick, soft interfacing layer inserted between the face fabric and the lining. It gives roman blinds a padded, luxurious appearance — folds are rounder and softer, and the blind appears more solid.

Trade-off: Interlining adds significantly to material cost and weight. The blind is harder to raise and the hardware must be more robust.

Best for: Formal sitting rooms in period properties, hotels, or any room where the blind is part of a high-end window dressing scheme. For fabric selection by weight and drape, see Best Fabrics for Roman Blinds.

Use the Roman Blind Calculator — select “Include lining” to get face and lining cut sizes.

See also: Best Fabrics for Roman Blinds and How to Calculate Cascade Roman Blind Fabric.