Blackout vs Room Darkening Claim Checklist

What this check establishes

A blackout, block-out, or room-darkening label establishes only what the cited source says for the identified material, product, family, or complete system under its stated conditions. It does not by itself establish how dark the installed room will be.

This checklist records the exact statement, the exact option it covers, any disclosed method and result, and the limit between source evidence and room geometry. Window measurements, curtain width and overlap, trim and returns, finished drop, and diagnosis of an installed light gap remain separate tasks.

What this checklist verifies

Complete the exact claim-condition verification record

Copy or print this record. Entries stay in your browser and are not submitted or saved.

Assign the evidence state and decision

1. No exact source statement: use UNKNOWN and VERIFY. Use NOT_APPLICABLE only when the selected item makes no covered claim.
2. Exact option unresolved: use DO_NOT_INFER and DO_NOT_RELY.
3. Exact maker statement found but method or result not disclosed: record the statement and its scope only, then use PARTIAL or UNKNOWN with VERIFY.
4. Method named without an exact result: describe the method scope only, then use PARTIAL and VERIFY.
5. Exact method, result, conditions, specimen, and variant established: use SUPPORTED and RELY_WITHIN_SCOPE only for that scope.
6. Family or category statement without exact product inclusion: use DO_NOT_INFER and DO_NOT_RELY for the exact product result.
7. Material or product evidence without complete-system or room proof: record the room result as UNKNOWN or DO_NOT_INFER and use the geometry handoff.
8. Complete-system evidence with mismatched or unknown frame, mount, dimensions, coverage, measurement, or conditions: use VERIFY.
9. Conflicting exact authoritative evidence: preserve both, use CONFLICT, and choose DO_NOT_RELY.
10. Stale or unavailable live source: retain a dated capture only as historical evidence; current status is UNKNOWN with VERIFY.

Interpret methods, product statements, and room results

The AATCC TM203 catalog entry and AATCC TM148 catalog entry describe methods for measuring light-blocking properties of specified textiles or related materials. A method’s existence does not establish that an exact product was tested or passed.

The EN 14501:2021+A1:2025 summary describes performance classification within defined product scopes. Do not apply a class to an arbitrary curtain without exact scope and conformity evidence.

The IKEA US light-filtering taxonomy describes IKEA’s own room-darkening and blackout tiers. It does not provide one cross-brand definition or a disclosed numeric test threshold.

The IKEA KORGMOTT 105.971.55 page makes a fabric-level light-blocking statement for the displayed dark-gray option. The page does not disclose a recognized test method, specimen result, installation geometry, or measured room outcome.

The IKEA MERETE 900.468.43 page describes the displayed white option as room darkening while allowing a small amount of light. No method, numeric result, geometry, or complete-room result is disclosed.

The Hunter Douglas room-darkening guide discusses edges, route holes, overlap, side channels, and layering. The IKEA FY26 Window Solutions guide separates light-control categories from complete window solutions. These sources support a handoff from source wording to room geometry; they do not prove another product’s result.

A complete-room conclusion requires exact complete-system or installed-room evidence with matching frame, mount, dimensions, coverage, measurement, and conditions. Material, category, or product wording cannot substitute for those facts.

Thermal performance is a separate claim. A light-control label does not establish insulation or another thermal result.

A maker’s privacy wording stays attached to the exact item and stated conditions. It does not guarantee privacy in every direction or lighting condition.

A maker’s screen-glare wording stays attached to the exact item and capture date. It does not establish universal glare prevention for other products or rooms.

Do not infer: No universal light-blocking percentage, whole-room darkness guarantee, sibling-variant result, automatic thermal or privacy result, UV result, sleep or medical benefit, general glare prevention, product ranking, or recommendation is established here.

Choose the next task only when its trigger applies

• If opening or order dimensions are missing, complete the window measurement record.
• If casing, obstruction, projection, or return geometry is unknown, complete the trim and return record.
• If panel width, fullness, overlap, returns, or center closure is unresolved, use width and overlap planning.
• If top or bottom coverage and finished length are unresolved, complete the drop and floor-clearance record.
• If an installed side, top, center, bottom, route-hole, or hardware gap is visible, use the light-gap troubleshooting checklist.
• For the general material-versus-gap concept, read blackout claims and light gaps.
• For terminology and the separate thermal question, read blackout, room-darkening, and thermal claim differences.
• For another curtain task, return to the Blackout Curtains Guide hub.