Blackout vs dimout curtains: fabric and fitting both count

01 / THE DETAIL

Start with the level of darkness you need

A presentation room, a film studio and a bedroom can have different light-control priorities. Describe the use, the time of day and any bright external light sources. “Blackout” as a project brief should include the whole opening, not just the face fabric.

The manufacturer calls Mercury a dimout fabric and states its light exclusion. That description should remain visible even when the percentage is high. We do not round a stated value into a promise of total blackout.

02 / THE DETAIL

Read product names with their descriptions

Premier Blackout includes “Blackout” in its name, while the manufacturer describes the cloth as 99% blackout. Eclipse Lining 2.8 is described as a three-pass blackout lining. These statements should be considered in their own source context; they are not a like-for-like ranking measured in one shared test.

Ask for a physical sample and the relevant technical documentation when a particular optical result matters. Consider the appearance from both sides and the proposed face-and-lining combination.

03 / THE DETAIL

Detail the top, sides and meeting point

Light can enter above the track, around outer edges, below the hem or between a pair of curtains. Track position, returns and overlap details need to be considered together. A good cloth specification alone cannot close an unplanned gap.

Our visual measuring guide shows overlaps and recesses. Send a dimensioned plan for shaped tracks or unusual openings, and confirm the details before manufacturing rather than adding an arbitrary amount to the configurator width.

04 / THE DETAIL

Keep light control and acoustic claims separate

A lining chosen for daylight control does not automatically create a tested acoustic assembly. Match any acoustic claim to evidence for the proposed layers and hanging condition. Read how to plan a lining and use our blackout curtain section to shortlist the light-control options.