Steps
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1.Indoors or outside
Outdoor signs in New Zealand face strong UV, wind and coastal salt. Choose a UV-stable grade of acrylic, polycarbonate or ACM for anything meant to last outside for years. Corflute suits short outdoor campaigns. PVC foam board is best kept indoors.
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2.Lit or unlit
For illuminated signs, light boxes and edge-lit displays, cast or opal acrylic gives the most even light spread and a clean polished edge. Polycarbonate is used where a lit panel also has to take knocks.
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3.Short campaign or permanent
Corflute is light, cheap and easy to print for real estate, election and event signs that come down after weeks or months. ACM, acrylic and polycarbonate are the materials for signs that stay up.
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4.Printed, routed or formed
PVC foam board and ACM take direct flatbed printing well and route cleanly into letters and shapes. PETG is the usual choice for vacuum-formed and heat-bent point of sale because it forms at a lower temperature and does not craze. Acrylic laser cuts with a flame-polished edge.
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5.Will it be knocked
In busy retail, schools, gyms and anywhere a sign can be hit, polycarbonate is many times tougher than acrylic and will not crack. Acrylic scratches less easily and stays clearer, so it suits displays that are looked at more than touched.
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6.Check thickness and size
Pick the thickness for the span and fixing (see the thickness guide), then the sheet size that gives the fewest offcuts. Full sheets are commonly 2440 x 1220 mm, so plan panel sizes around that.
Tips
- Leave the protective film on until the sign is installed.
- For outdoor acrylic, allow for expansion: drill fixing holes oversize and do not clamp the sheet tight.
- Ask for a UV-stabilised grade for anything facing north in direct sun.
- Polycarbonate scratches more easily than acrylic. Use a hard-coated grade where it will be cleaned often.
Material by job, at a glance
Illuminated signs and light boxes: opal or clear cast acrylic. Shopfront and reception signs: acrylic, ACM or both, with acrylic letters on an ACM backing. Point of sale, brochure holders and formed displays: PETG. Sneeze guards, counter screens and anything that may be hit: polycarbonate. Real estate, election and event signs: corflute. Indoor printed signs, exhibition panels and lightweight mounting: PVC foam board. Outdoor flat signs, building fascias and long-life printed panels: ACM.
Acrylic or polycarbonate for a clear panel
Both are clear, but they behave differently. Acrylic is stiffer, clearer and more scratch resistant, polishes to a glass-like edge and costs less. Polycarbonate is far more impact resistant and bends without cracking, but scratches more easily and yellows over time unless it is a UV-protected grade. If the panel will be looked at, choose acrylic. If it will be hit, choose polycarbonate. Our acrylic vs polycarbonate comparison goes into more detail.
Fixing outdoor signs
Plastics expand and contract with temperature much more than timber or metal, and a dark sign in summer sun can move several millimetres over its length. Drill fixing holes larger than the screw, use stand-offs or washers that let the sheet move, and leave a small gap at frame edges. ACM moves far less than solid plastic sheet, which is one reason it is used for large outdoor panels.