There’s a specification habit that shows up for acoustic board: the NRC rating gets scrutinised carefully, and the finish gets picked from a catalogue swatch. One gets treated as science, the other as decoration. In reality, they’re both technical decisions, and getting the finish wrong can quietly undermine a product that looks perfect on paper.

This is worth understanding at the specification stage, not after installation.

How the Surface Finish Affects Acoustic Board Performance

Sound absorption works because energy passes into a material and gets converted to heat through friction inside its fibrous or cellular structure. The surface finish controls how much sound gets that chance.

A finish that blocks the face of the material also blocks the pathway. This is why the same acoustic board can deliver very different NRC values depending on what covers it.

Painted Surfaces

Spraying or rolling paint over an acoustic board is one of the most common ways performance gets compromised on-site. Even a single coat of latex paint, if it films over the surface rather than penetrating it, can drop the NRC of a fabric or fibre board meaningfully. The panel looks the same. The spec sheet still shows the original NRC. But the space doesn’t behave the way the acoustic model predicted.

If a painted finish is required, perforated facings or paints specifically formulated to remain acoustically transparent are the right route. This is worth flagging to clients early, particularly when repainting is planned during fit-outs or refurbishments. Fabric wrapping handles the same challenge differently, and generally more reliably.

Fabric Wrapping

Fabric-wrapped acoustic boards remain one of the most reliable ways to maintain NRC performance while offering genuine design flexibility. The key variable is the fabric itself: an open-weave textile allows sound to pass through to the absorptive core, while a tightly woven or coated fabric reduces that transmission considerably.

This means the fabric spec matters, not only the colour or texture. When sourcing custom colours for a project, confirming the acoustic board transparency of the fabric before sign-off is a step that occasionally gets missed under deadline pressure.

For projects where the brief calls for a harder material, perforated facings introduce a different set of variables worth understanding.

Perforated Facings

Wood, metal, and gypsum perforated acoustic panels work differently. They rely on the perforation ratio (the percentage of open area) to determine how much sound reaches the absorptive layer behind them. A higher perforation ratio generally gives better mid-to-high frequency absorption; lower ratios shift the performance curve or reduce it.

This becomes a genuine design variable. A wood perforated panel with a 15% open area will look and behave very differently from one at 25%. When the brief calls for a warm material aesthetic alongside acoustic performance, understanding this relationship helps make better decisions at the concept stage rather than the remedial one. The same logic applies to acoustic wall panels with perforated wood or metal facings, where the perforation ratio is a specification decision, not a visual one.

The Finish as a Design Decision, Not an Afterthought

Acoustic boards live on walls and ceilings. They occupy a significant surface area. In a well-designed commercial space, they’re not background elements; they’re part of the material palette.

This is where the finish choice does double duty. It needs to perform acoustically and sit within the spatial concept without looking like something bolted on to fix a problem.

1. Matching Material Palettes

Getting perfectly customised acoustic solutions that integrate with a specific material palette is harder than it should be. Standard catalogues offer a range, but projects often call for something more specific: a particular tone of fabric to complement a joinery detail, a perforation pattern that references a geometry elsewhere in the space, or a printed panel that carries a brand graphic without sacrificing absorption.

This is not an unusual ask. It’s where acoustic specification meets interior design in the most direct way.

2. Durability and Maintenance Considerations

The finish also determines how the panel ages. High-traffic zones need different surface specifications than boardroom walls. A fabric-wrapped panel in a hospital corridor will show wear differently from one in a hotel lobby. Metal-faced panels can be wiped down; fabric panels need more careful maintenance protocols.

Specifying without this lens risks a product that performs well at handover and looks compromised eighteen months later.

Getting the Specification Right

Treat the finish as a technical specification, not a styling choice. That’s the practical takeaway.

When reviewing acoustic board options, confirm these before locking in a specification:

• Does the intended finish maintain the NRC rating shown in the data sheet, or is that figure based on a different surface condition?
• What is the acoustic transparency of the proposed fabric?
• If a perforated facing is involved, what is the perforation ratio, and how does that affect frequency response?
• How does the finish perform given the specific use context: humidity levels, cleaning requirements, and footfall?

These questions don’t add complexity to the process. They prevent rework.

How Unidus Acoustics Approaches This

With 40 years of expertise in acoustic solutions, Unidus Acoustics works across the full range of surface finishes: fabric-wrapped wall panels, perforated wood and metal facings, PET panels, printed acoustic panels, and more. The approach is to specify and manufacture based on both acoustic requirements and design intent, never one at the expense of the other.

U-TONE wall panels, acoustic ceiling systems, and baffle solutions are available with custom finishes. The team provides technical documentation, including NRC ratings and fire certificates for tender submissions, making the specification process as useful to the design workflow as possible.

If you’re specifying acoustic boards for an upcoming project, we’d be glad to partner with you on getting the finish right. Contact us now!