Museum Lighting in 2026

Why This Guide Exists

Walk into any European museum tender in 2026 and you will see three acronyms repeated on every spec sheet: TM-30, RG0 and EN 17037. Five years ago a CRI ≥ 90 line was enough to win the job. Today it will get your submission rejected before the conservator even opens the photometric file.

This guide is written for the people who actually have to deliver these projects — independent lighting designers, M&E consultants and architectural contractors selling into galleries, archives, heritage interiors and corporate art collections. No marketing fluff. Just the parameters, the math and the mistakes.

1. TM-30: Why CRI Alone Is Finally Dead

CRI (Ra) only averages 8 pastel test colours. It tells you almost nothing about how a fixture renders deep reds, saturated blues, or skin tones on a portrait.

IES TM-30-20 evaluates 99 colour evaluation samples (CES) and reports two numbers you should read on every datasheet:

• Rf (Fidelity) — how accurately colours are rendered vs. the reference. Target Rf ≥ 90 for galleries, ≥ 95 for paintings and textiles.
• Rg (Gamut) — how saturated colours appear. Target Rg between 98 and 105. Below 95 colours look washed out; above 110 the fixture is artificially boosting saturation (bad for conservation, sometimes wanted in retail).

A "CRI 95" fixture with Rf 82 / Rg 92 is a worse museum fixture than a "CRI 92" one with Rf 93 / Rg 100. We see this on bid sheets every week.

Field tip: ask suppliers for the TM-30 colour vector graphic (the circular plot). If they cannot send it within 24 hours, they are reselling someone else's chips and have not measured the finished fixture.

2. RG0: the Photobiological Safety Line Conservators Care About

IEC/EN 62471 classifies every light source into a Risk Group based on blue-light hazard:

For paper, textiles, photographs and natural-history specimens, conservators will also ask for UV ≤ 75 µW/lm and IR filtered — most quality museum-grade LEDs already exceed this, but you must put the number on the submittal.

Lux + hours = damage. ICOM and CIE 157 recommend:

• Highly sensitive (textiles, watercolours, manuscripts): ≤ 50 lux, max 50,000 lux·h/year
• Sensitive (oil paintings, leather, bone): ≤ 150 lux, max 480,000 lux·h/year
• Insensitive (stone, metal, ceramic, glass): ≤ 300 lux, no annual cap

Pair RG0 fixtures with DALI-2 dimming and occupancy sensors so the gallery only hits target lux when visitors are present. This single design move can extend artwork life by decades.

3. EN 17037: Daylight Is Part of the Spec Now

EN 17037 (Daylight in buildings) became the harmonised European standard and is being written into national building codes from Germany to Poland. For a museum, the implications are:

• Daylight provision D ≥ 1.8% on 50% of the reference plane for circulation and lobbies.
• View out, sunlight exposure and glare protection (DGP < 0.35) are now mandatory in occupied spaces.
• Artificial lighting must complement, not replace daylight. CCT-tunable fixtures (2700K–5000K) are now standard in any new-build cultural project.

If your fixture cannot tune CCT smoothly across the day to track daylight, you will lose the LEED v4.1 / BREEAM credits the architect is chasing. That is what kills bids in 2026 — not price.

4. the Five Mistakes We See Contractors Make Every Month

1. Quoting CRI 90 because the chip datasheet says so. The chip is not the fixture. Optics, driver and thermal design all shift Rf/Rg by 3–8 points. Demand a finished-fixture LM-79 report.
2. Mixing batches with ≥ 3 SDCM. Two fixtures next to each other on the same painting and one looks pink, one looks green. Specify SDCM ≤ 2 on the PO and reject the shipment if the supplier cannot prove it.
3. Ignoring driver flicker. PstLM ≤ 1.0 and SVM ≤ 0.4 are mandatory for 4K video documentation of the collection. Cheap PWM dimming destroys both.
4. Forgetting beam angle layering. Galleries need at least three beam families: 10–15° for accent on individual works, 24–36° for wall-wash, 60°+ for ambient. One beam angle for everything is the fastest way to get a redesign request from the conservator.
5. No DALI-2 certification. Older DALI gear works "most of the time". DALI-2 (DiiA-certified) is the only spec accepted by major EU museum integrators in 2026. Check the certificate number on the DiiA website before quoting.

5. a 60-second Specification Checklist

Copy this into your next museum submittal. If a supplier cannot tick every line, walk away.

• Rf ≥ 90, Rg 98–105 — TM-30 vector graphic attached
• CRI Ra ≥ 95, R9 ≥ 90, R12 ≥ 85
• Photobiological safety: RG0 per IEC 62471
• UV ≤ 75 µW/lm, IR filtered
• SDCM ≤ 2 across the entire batch
• PstLM ≤ 1.0, SVM ≤ 0.4 (flicker)
• DALI-2 certified driver, smooth dim 1–100%
• CCT options 2700 / 3000 / 3500 / 4000 K minimum, ΔCCT ≤ 100 K
• Beam angle family: 10° / 24° / 36° / 60°
• LM-79 + LM-80 + TM-21 reports on finished fixture, not the chip
• Minimum 5-year warranty, L90/B10 ≥ 50,000 h

How XHLWX Builds for This Spec

We manufacture museum-grade track spots, recessed downlights and showcase linear LEDs in our Shenzhen facility, all measured per LM-79 and certified RG0. Every project ships with the full TM-30 + LM-79 + LM-80 + DALI-2 documentation pack — no chasing supplier emails the week before site handover.

If you are scoping a museum, gallery or heritage project anywhere in Europe and want a free photometric study and mock-up sample, email me directly at len@led-project-light.com or use the contact form. We respond within 48 hours with a sealed-bid-ready proposal.