The lining behind a curtain affects how it hangs, how much light it lets through and how cosy the room feels — often as much as the face fabric you choose. In short: unlined curtains are light and airy, standard linings add body and protect the fabric, blackout linings stop light passing through the curtain, and interlining adds a soft middle layer for fullness and warmth. None of them, on their own, makes a room completely dark.
The main types of curtain construction
Unlined
Just the face fabric. Unlined curtains filter light softly and suit sheers, voiles and relaxed, informal looks. They offer little privacy at night when lights are on inside, and the fabric is more exposed to sunlight. See sheer and voile curtains.
Standard lined
A separate backing layer, usually a plain cotton or cotton-blend lining, sewn behind the face fabric. It helps the curtain hang better, adds a little body, gives a neat appearance from outside and helps protect the face fabric from sunlight. Standard lining reduces light but does not block it.
Blackout lined
A lining designed to prevent light passing through the curtain fabric. It is the usual choice for bedrooms and nurseries. Blackout linings come in different weights and constructions, which can affect how the curtain drapes. See blackout curtains.
Interlined
An extra, soft layer placed between the face fabric and the lining. Interlining gives curtains a fuller, more luxurious look, helps them drape in deep, rounded folds and can improve insulation, making a window feel less cold on winter evenings. Interlining comes in different weights. See thermal and interlined curtains.
Combined options
Some constructions combine blackout performance with interlining, or use a thermal lining designed to improve comfort. Where these are offered, they can suit bedrooms in older, draughtier homes. Availability depends on the fabric and range.
Blackout lining does not mean a dark room
This is the most important point in this guide. A blackout lining stops light passing through the curtain itself. Light can still enter:
- around the outer edges of the curtains;
- above the track or pole;
- below the hem;
- through the centre where the two curtains meet;
- at the returns, where the curtain turns back towards the wall.
How dark the room becomes depends as much on the hardware and how the curtains are made and fitted as on the lining.
Why the track, overlap and fitting matter
- Width and overlap — curtains that extend well past the window and overlap in the centre leave fewer gaps.
- Height — fitting the track or pole higher above the window, and closer to the ceiling, reduces light spilling over the top.
- Returns — curtains that return to the wall at the sides close off the edge gap.
- Overlap arms — some tracks allow the two leading edges to overlap rather than just meet.
- Pelmets or covered heads — can help block light escaping above the curtain.
See tracks and poles for the options.
Which construction suits which room?
- Bedrooms — blackout lining as a minimum; interlined blackout for extra warmth and a softer drape.
- Nurseries — blackout lining, often layered with a blackout blind for the darkest result.
- Living rooms — standard lining or interlining, depending on the look and how cold the window feels.
- Period homes with large sash windows — interlining is a traditional choice for fullness and comfort.
- Kitchens and bathrooms — generally better suited to blinds, because linings and interlinings can absorb moisture.
When a blind and curtain together is better
If darkness is the priority — for shift work, light sensitivity or a young child — a blackout blind fitted close to the window with blackout-lined curtains in front will usually get closer to a dark room than either on its own. The blind deals with most of the light; the curtains close off what gets round the edges. See Blackout Curtains vs Blackout Blinds and layered window treatments.
A note on performance claims
Linings and interlinings can make a window feel warmer and a room feel softer, but the effect depends on the fabric, the construction, the window and the fit. We do not quote energy savings or acoustic figures without test data for the specific product.
We can bring the question of linings into a free home survey, looking at the window, the track position and how dark or warm you want the room to be.
Frequently asked questions
Do blackout curtains make a room completely dark?
No. The lining stops light through the fabric, but light can still come around the edges, over the top and through the centre.
What is interlining?
A soft layer between the face fabric and the lining. It adds fullness, helps the curtain drape and can improve insulation.
Can I have blackout and interlining together?
Often, yes, depending on the fabric and range. The combination is heavier, so the track or pole needs to be suitable.
Do lined curtains help keep a room warm?
They can make a window feel less cold, particularly when interlined and well fitted. They do not replace efficient glazing or draught-proofing.