Sign materials
Sign substrates, and how each one fails
Every material page on the internet is written by whoever is selling the sheet, so they all say durable and versatile and stop there. These pages carry the other half: which thickness cups in the sun, which way the flutes have to run, what heat does to it on a flatbed, and roughly what a sheet costs.
Written by a shop, not a supplier. If we have something wrong, tell us and we will fix it.
Coroplast
Corrugated plastic, corflute, fluted polypropylene
The yard sign material. Cheap, light, weatherproof for a season or two, and the one substrate where getting the flute direction wrong ruins the job.
Specs and failure modes →ACM
Aluminum composite, Dibond, Alupanel, Max-Metal
Two thin aluminium skins bonded to a plastic core. The default for a permanent flat sign that has to stay flat.
Specs and failure modes →Expanded PVC
Sintra, Komatex, Palight, foam PVC
Solid plastic sheet that machines like butter and looks expensive indoors. Outdoors it moves more than people expect.
Specs and failure modes →Aluminum
Sheet aluminium, .040, .063, blanks
The traffic and parking sign material. Effectively permanent, completely rigid, and unforgiving of a bad hole.
Specs and failure modes →Acrylic
Plexiglas, Perspex, Lucite, PMMA
What you use when the sign has to look expensive or has to light evenly. Cast and extruded are not interchangeable.
Specs and failure modes →MDO Plywood
Medium density overlay, signboard plywood
Exterior plywood with a resin impregnated paper face. The traditional billboard and construction sign material, and still the right answer for big and temporary.
Specs and failure modes →Foam Board
Foamcore, Gatorfoam, display board
Indoor only, light as anything, and dented by a fingernail. Perfect for the job it is actually for.
Specs and failure modes →Magnetic Sheet
Vehicle magnets, magnetic receptive sheet
Removable vehicle graphics for people who cannot commit to a wrap. Simple to make, and the failures are all in the aftercare.
Specs and failure modes →Ballpark trade prices for a 4 x 8 sheet as of August 2026, before markup. Yours will differ by supplier, region and how much you buy at once — treat these as a sanity check on a quote, not a price list.
Pricing a job right now?
The free sign price calculator prices by size and material the way a shop actually quotes, and the rest of the tools cover letter height, wrap area and print file checks. No signup on any of them.