Buying guide

Curtain Linings Explained: Blackout vs Thermal vs Sateen

Curtain linings explained for made-to-measure buyers comparing blackout, thermal and sateen by room use, light control, insulation and fabric finish.

British Made Interiors19 July 2026

There is no universal best curtain lining. Choose blackout when reducing light through the curtain fabric is the priority, thermal when warmth and cold-window comfort matter most, and sateen when the main goal is a lighter everyday lining with a neat finish. Before you order, check the room, fabric colour, fabric weight and the lining choices available for your chosen made-to-measure curtain fabric.

For bedrooms, nurseries, media rooms and sleep-led spaces, start with blackout, while remembering that edge gaps and the full window treatment affect whole-room darkness. For colder or draught-prone rooms, start with an insulation-first lining because its construction is designed for warmth. For living rooms and design-led everyday curtains, start with sateen when drape, sheen and a lighter finish matter more than maximum light control or added warmth.

Key Takeaways

Choose blackout when the main problem is light through the curtain fabric.
Choose thermal when the room feels cold, draught-prone or uncomfortable near the window.
Choose sateen when you want an everyday lining with a softer hang and neat finish.
Do not treat the lining as a separate afterthought. Match it to the room, the fabric and the final look you want.

What Curtain Linings Do

Curtain linings sit behind the face fabric. They help shape how your made-to-measure curtains look, hang and perform. A lining can improve privacy, reduce light through the fabric, add warmth, protect the face fabric and change the finished drape. General curtain-lining guides also describe these roles across privacy, insulation, elegance, terminology and fabric choice.^[6]^[8]^[9]^[10]

At British Made Interiors, the practical choice often comes down to three linings: sateen, blackout and thermal. Blackout is the darkness-first option. British Made Interiors describes blackout as composed of 3 separate layers of fabric and termed “3 Pass Blackout”^[1]. Thermal is the warmth-first option. It is described as made from a blend of Polyester and Cotton as well as a special thin foam layer^[1]. Sateen is the finish-led everyday option: Sateen lining is made from 100% cotton and produced in a way that gives it is well known sheen finish^[1].

That is why the right question is not “which lining is best?” It is “what problem does this room need the curtains to solve?” British Made Interiors also notes that studies suggest up to 35%^[1] of a house’s heat can be lost through windows, so cold-window comfort can be a real part of the decision, even though that figure is a broad heat-loss context rather than a promise for any one curtain order.

Linings Explained - Sateen, Blackout & Thermal — Sateen, blackout and thermal linings solve different curtain problems. Use the image as a simple way to compare the options, not as proof of performance.

Blackout vs Thermal vs Sateen: The Quick Decision Table

Blackout and thermal are not the same choice. Blackout is the better fit for darkness-first rooms, while thermal is the better fit for warmth and insulation. Sateen is different again: it is a lighter, finish-led lining when drape and fabric appearance matter more than maximum light reduction or extra warmth. If you already know your main room problem, use this table as your first filter.

Blackout, Thermal and Sateen Curtain Linings Compared
Situation	Best choice	Main trade-off	Construction or numeric cue	Next action
Bedroom, nursery, media room or shift-work sleep where reducing light is the main goal.	Blackout option	You may expect complete whole-room darkness from lining alone, but the wider window treatment and edge gaps affect results.	3 Pass construction for light through the material.	Compare blackout as the darkness-first option, then check our lining information or made-to-measure curtain range.
Cold, draught-prone or older room where warmth matters more than maximum darkness.	Insulation-first lining	You may confuse thermal with blackout or assume every thermal curtain gives the same measured heat-loss result.	Window heat-loss context: up to 35%^[1]; no fixed saving promised.	Check the thermal construction and choose the lining alongside your curtain fabric.
Living room, everyday curtain choice, or design-led room where fabric hang and a neat finish matter most.	Sateen option	You may underweight lining colour, fabric weight and fullness or hang effects.	1-layer, 100% cotton construction for a lighter finish.	Use sateen as the finish-led baseline, then check fabric compatibility before ordering.
You are ready to order but unsure how the lining choice connects to made-to-measure curtains.	Use our lining guide, then browse our made-to-measure curtains	It is easy to get pulled into over-detailed measuring advice before you have chosen the right lining.	Choose the lining first, then choose the curtain fabric that suits your room.	Start with our lining guide, then browse our made-to-measure curtains.

Choose by Room Use First

Choose blackout lining when reducing light through the curtain fabric is the main priority, especially for bedrooms, nurseries, media rooms or sleep-led spaces. One vendor lining guide recommends 100% blackout^[2] for bedroom curtain lining, but treat that as product guidance, not a guarantee that every finished room will be fully dark. Fabric, fit, returns, track or pole choice and side gaps still matter.

If you are dressing a bedroom, start with the sleep need first. A pale fabric in a bright east-facing room may need a different lining choice from a heavy patterned fabric in a shaded guest room. If you want a more dressed, hotel-style result, our ideas on blackout curtains and interlining for a hotel-style bedroom can help you think about comfort and finish without turning the decision into a measuring task.

For a cold sitting room, bay window or older house, an insulation-first choice is usually the more direct fit. It is made to support warmth, while blackout is made to reduce light. For an everyday living room where you want the fabric to hang softly and show its colour well, sateen is often the calmer choice. Choose sateen when the room needs an everyday lining with a softer finish and good drape rather than the stronger light control of blackout or the insulation focus of thermal.

Light Control and Insulation Tradeoffs

The biggest mistake is to ask one lining to solve every problem. Blackout helps with light through the material. Thermal helps with cold-window comfort. DotcomBlinds frames blackout and thermal curtains around different main purposes, with blackout focused on light blocking and thermal focused on heat retention.^[3]

For light control, blackout is the strongest of the three choices. British Made Interiors says the multiple layers in its 3 Pass Blackout work to block almost all light from passing through the material when used with the proper window treatment.^[1] The caution is important: blackout fabric opacity is not the same as whole-room darkness. uBlockout reports that it analysed 47 blackout window treatments and found standard blackout curtains could still show room-centre light leakage because of edge gaps.^[5] If sleep is the point, read more on how blackout curtains can help you sleep, then check the final curtain style, pole or track, and fit.

For warmth, choose thermal lining when insulation and cold-window comfort matter more than maximum darkness. DotcomBlinds’ comparison table says thermal curtains can reduce heat loss by up to 25%^[3], but that is a vendor table claim and does not set a fixed result for every home. James Dunlop Textiles reports that New Zealand’s Energy Efficiency and Conservation Authority estimates professionally fitted, lined drapery can reduce window heat loss by 40-60%^[4] when closed, which again depends on fit, closure and conditions. For a narrower thermal follow-up, see our note on whether thermal curtains are effective.

Check Fabric Compatibility Before You Choose

Sateen can be a good everyday lining for drape and finish, but fabric compatibility still matters because lining colour, fabric lightness and thickness can affect the final look and hang. British Made Interiors describes sateen as a lightweight material composed of one layer of fabric and so hangs well as both curtains and roman blinds^[1]. That makes it a useful starting point for many design-led rooms, especially where you do not need blackout or added insulation.

Still, do not choose the default lining without looking at the fabric. A very pale fabric can be affected by the lining colour behind it. A heavier fabric may behave differently from a light cotton or linen-look cloth. British Made Interiors’ lining information also warns that lining colour should be matched to the main fabric, including avoiding cream sateen behind a lightweight white fabric.^[1]

As a caution on finished feel, in a Trustpilot review, Abigail described noticing lining thickness and the way it affected fullness and hang in blinds from British Made Interiors. Treat that as one person’s experience, not a general rule about all blinds or curtain linings, and use it as a prompt to check lining thickness, fabric weight and finished look before you order.^[12]

How to Order With More Confidence

Before ordering, match the lining to the room problem first, then check fabric colour, fabric weight, lining thickness and the made-to-measure curtain options so the finished curtains meet your light, warmth and drape expectations. If the room is a bedroom, start with blackout. If the window is cold, start with thermal. If the room is design-led and you want a lighter everyday finish, start with sateen.

Then move from the idea to the product choice. Use our Sateen, Blackout and Thermal lining information with our made-to-measure curtain range. Lining availability can vary by fabric and curtain option, so check the choices shown for the curtain you like before you order.

In a Trustpilot review, SID Leeds described ordering bedroom curtains in a William Morris fabric, noting that the material was not immediately available and took more than two months to be made, but also mentioning communication during the wait and curtains that were well made and fitted perfectly. Use that as a reminder to check fabric availability and ask questions before placing a made-to-measure order.^[11]

If you still need measurement support, use our curtain measuring guides as a support step rather than trying to solve lining, fabric and measuring all at once. The better order is simple: room problem first, fabric and lining together second, measuring support only when you are ready to confirm the details.

Frequently Asked Questions

Is blackout always better than thermal?

No. Blackout is better when light reduction is the main need. Thermal is better when warmth and cold-window comfort matter more. They solve different problems, so choose by the room rather than assuming one is always superior.

Will blackout make a room completely dark?

Not by itself. A blackout lining can reduce light through the curtain fabric, but whole-room darkness also depends on the wider window treatment, fit and edge gaps. If complete darkness is critical, check the full curtain setup, not just the lining.

Can I choose sateen for bedroom curtains?

Yes, if the bedroom does not need strong light control or extra insulation. Sateen is a finish-led, everyday lining. For a bright bedroom, nursery or sleep-led room, blackout is usually the safer starting point.