Acrylic vs ACM vs Aluminium — Which Sign Material Is Right?
Three materials dominate Australian flat signage: clear or opaque acrylic, Aluminium Composite Material (ACM), and solid aluminium sheet. They look similar from ten metres away. Up close, and over ten years of weather, they behave very differently.
This guide is a head-to-head comparison written for people specifying signs, not making them. If you're trying to work out whether you can save money by downgrading an acrylic reception sign to ACM, or whether your coastal client actually needs solid aluminium, this is the answer.
All pricing figures are AUD ex GST, 2026 retail, for a standard 600 × 400mm panel printed single-sided. Prices scale roughly linearly with area.
The three materials at a glance
| Property | Acrylic | ACM (3mm) | Solid aluminium (2mm) |
|---|---|---|---|
| Weight (per m²) | 3.5 kg | 4.6 kg | 5.4 kg |
| Cost (600×400mm print) | From $95 | From $90 | From $220 |
| Lifespan outdoors | 5–8 yrs | 8–10 yrs | 15+ yrs |
| Indoor / outdoor | Both | Both | Both |
| Can be edge-lit | Yes | No | No |
| Can be printed direct | Yes | Yes | Yes |
| Can be laser cut | Yes (to 40mm) | No (routed) | No (routed/waterjet) |
| Best for | Reception, indoor feature, edge-lit | General outdoor, shopfronts, hoardings | Premium reception, high-traffic, wayfinding |
Acrylic — the light, crystal material
Acrylic (PMMA) is what you think of when you think of "perspex." It's cast or extruded into sheets from 2mm to 40mm, available clear or in hundreds of solid, frosted and metallic colours. Cast acrylic is the premium grade — flame-polished laser edges, better print adhesion, more stable under UV. Extruded acrylic is cheaper and fine for internal work but will yellow faster outdoors.
Acrylic's killer feature is that it can be edge-lit — meaning LEDs around the perimeter make the whole sheet glow from within. That's why acrylic dominates reception signs and premium indoor wayfinding.
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Acrylic Signs
Cast and extruded acrylic signs in clear, coloured and frosted — 3mm through 20mm. Laser-cut edges, UV direct printing, standoff or flush mount.
ACM — the default all-rounder
ACM (Aluminium Composite Material) is the Toyota Corolla of signage: cheap, reliable, lasts forever, gets the job done. A sandwich of two thin aluminium skins over a polyethylene core, it's flat, rigid, weatherproof, takes UV print cleanly, and costs less per square metre than either acrylic or solid aluminium.
The trade-off is that ACM always reads as "sign panel." You can upgrade the look with brushed-finish ACM, which genuinely does look like real brushed metal at a fraction of the cost.
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Acm Signs
Standard 3mm ACM in white matte, gloss, and stock colours — the default material for Australian outdoor signage in 2026.
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Brushed Acm Signs
Brushed-finish ACM — the look of real brushed aluminium with the pricing of composite panel. Ideal for corporate reception and premium shopfronts.
Solid aluminium — the heirloom option
Solid aluminium sheet, typically 1.2mm, 1.6mm or 2mm, is the premium end of flat signage. It's heavier, more expensive, and feels substantial when you hold it. It won't de-laminate (ACM can, eventually, in extreme heat), won't yellow (acrylic will, slowly, outdoors), and lasts 15+ years with proper finishing.
Solid aluminium is the right call when the sign will be touched, cleaned regularly, or seen close-up in a premium environment — reception panels, corporate wayfinding, high-end retail interior signs.
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Aluminium Signs
Solid aluminium sheet signs in 1.2mm, 1.6mm and 2mm — premium reception and wayfinding. Can be painted to any RAL or Pantone colour.
The coastal question
East-coast Australia — especially within 1km of the coast — is hard on signage. Salt spray corrodes untreated metals; UV index above 10 (summer peak in Sydney is 12–13) fades prints. For coastal installs, our recommendations are:
- Prefer ACM or solid aluminium over acrylic for outdoor exposure
- Specify marine-grade aluminium if using solid metal within 500m of surf
- Always UV-laminate printed faces for coastal installs — adds 2–3 years to print life
- Avoid Colorbond within 200m of surf unless you use the marine-grade product and accept the cost
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Colorbond Signs
Colorbond steel signs in standard BlueScope colours — for residential and heritage environments where the sign needs to tone with Colorbond cladding.
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Foam Pvc Signs
Foam PVC sheet signs — lighter than ACM, less durable outdoors, but perfect for indoor retail and display where weight matters.
Decision tree
- Indoor feature sign, backlit — acrylic
- Indoor reception with premium feel — brushed ACM or solid aluminium
- Outdoor shopfront fascia — standard ACM
- Outdoor building facade, high rise — fire-rated ACM (A2 core)
- Outdoor at coast, premium — solid marine-grade aluminium
- Temporary outdoor (< 2 years) — corflute, not any of the above
Next steps
If you know the material, jump straight to the calculator on the relevant product page for an instant supply price. If you're on the fence between two options — or your location is unusual (coastal, high-rise, heritage) — send us a photo and the dimensions, and we'll come back within one business day with a specific recommendation.
Written by
Platinum Signs
Sydney-based commercial signage manufacturer
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