Composite Panel Guide: ACM Types, Uses and Cut to Size
Composite panel guide: what ACM is, core and finish options, common uses and how to order aluminium composite sheet cut to size online Australia-wide.
Search for a composite panel and you will find everything from timber-based building boards to fibre cement sheets. In the plastics and signage trade, the term almost always points to one product: aluminium composite material, usually shortened to ACM. It is flat, stiff, light and takes a finish well, which is why sign makers, shopfitters and builders keep reaching for it. This guide explains what a composite panel is, the options you will come across, where it works best and how to order it cut to size.
What is a composite panel?
A composite panel is a sandwich. Two thin outer skins are bonded to a core, and the combination behaves differently from any one layer on its own. With ACM, the skins are aluminium and the core is a plastic-based material. The aluminium gives you a smooth, durable, paintable face. The core keeps the panel light and stops it from feeling like a flimsy metal sheet.
The result is a panel that holds its flatness over large spans, resists weather and can be cut, routed and folded with the right technique. You can see the full range and current options on the ACM sheet product page .
Composite panel options to consider
Core type
The core is the biggest decision. A polyethylene core is the traditional choice for signage and interior work because it is light and easy to process. Fire-retardant cores use mineral-filled material to improve fire performance. Australian building rules are strict about what can go on the outside of certain buildings, and polyethylene-core panels are restricted for external cladding in many cases. If your job involves cladding, confirm requirements with your designer or certifier before you order.
Thickness and skin
Thicker panels are stiffer and suit larger unsupported areas, such as big signs and wall linings. Thinner panels are easier to fold and cheaper to freight. The thickness of the aluminium skin also affects stiffness, dent resistance and how the panel behaves when routed and folded. Check the options on the product page for what is currently available.
Finish and colour
Composite panels come with coated faces in a range of colours and finishes, including gloss, matt and metallic looks. For signage, a smooth coated face suits digital printing, vinyl application and paint. For architectural or interior use, the finish is part of the design, so check samples where colour matching matters. Many panels also carry a protective film that should stay on until installation.
Where composite panels are used
Because the panel is flat, rigid and presentable straight from the sheet, it turns up in a lot of places:
Signage: shopfront signs, directional signs, real estate boards, pylon faces and trade signage, where the panel stays flat and takes print well.
Shopfitting and displays: counter fronts, feature walls, display backing panels and point-of-sale stands.
Interior linings: wall panels, ceiling features and partitions where a clean, wipeable face matters.
Vehicle and trailer work: lightweight panels for fit-outs, enclosures and bodywork, where weight is a constraint.
External facades and cladding: only with the correct core and compliance sign-off, given the building-code rules mentioned above.
Composite panel vs other sheet materials
ACM is not always the right answer. If you need a transparent or translucent panel, you are looking at acrylic or polycarbonate instead. If you need a lightweight, low-cost board for short-term signage, a plastic sheet such as corflute may be enough. And for impact-heavy or chemical-exposure jobs, an engineering plastic usually beats a composite panel. The material selection guide can help you narrow it down, and you can browse the full range of plastic sheets if you want to compare options.
Working with composite panel
ACM is forgiving, but a few habits make a big difference to the finished result:
Keep the protective film on while cutting and handling, and support the whole sheet to avoid scratching the face.
Use sharp, fine-toothed blades or router bits suited to aluminium and plastic.
Allow for thermal movement on large outdoor panels, since aluminium expands and contracts with temperature.
Seal exposed edges where moisture could get to the core, especially outdoors.
For complex shapes, holes or repeat parts, consider CNC router services instead of hand cutting, since a programmed cut gives you consistent edges and accurate profiles.
How to order composite panel from Plastic Online
Ordering is straightforward. Start on the ACM product page , choose your options and enter the dimensions you need. If you prefer to work through pricing first, the pricing calculator gives you a live figure, and the cut-to-size service means you receive panels ready to fit rather than full sheets you have to break down yourself.
Before you order, measure carefully, decide whether you need extra for waste or fixing allowances, and confirm the core and finish suit your application and any compliance rules. If you are unsure about the right grade for a job, or need shapes and cut-outs beyond straight cuts, contact the team and describe what you are building.
Choosing the right composite panel
A good composite panel gives you flat, rigid and good-looking sheet without the weight and cost of solid metal. Match the core to the application and check compliance for anything external, choose a thickness that suits the span, and pick a finish that suits how the panel will be used. Get those three right and ACM is one of the most practical sheet materials in the workshop.
Ready to start your project? Get an instant cut-to-size price for composite panel from Plastic Online. Choose your panel, enter your dimensions and see your price straight away, with delivery Australia-wide.