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Corrugated Plastic vs. PVC vs. Foam Board vs. Aluminum: Which Sign Material?

Corrugated plastic, foam board, PVC, aluminum or ACM? Here's how each sign material compares indoors and out, and which one fits your job.

6 min read Updated November 1, 2026 By Bklet Co

Aluminum office hours sign screwed to a brick wall next to a dental office door

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Pick corrugated plastic for light, temporary outdoor signs like yard signs. Pick foam board for indoor signs at events, PVC for rigid indoor signs and short-term outdoor use, and aluminum or aluminum composite (ACM) for signs that need to stay up outside. Add reflective material when people need to see the sign at night.

That's the short version. Below we compare each material side by side, explain where each one shines, and help you match the material to where your sign will live. Every material prints in full color, ships the next business day when you order by 12pm, and ships free.

Shop signs by material

Each card below is a different material. Tap through to see sizes, single- or double-sided options and live prices.

Sign materials side by side

Material	Indoor / outdoor	Rigidity	Weight	Best for	Typical uses
Corrugated plastic	Outdoor (temporary)	Flexible, holds its shape on a stake	Very light	Short-term outdoor messages	Yard signs, open houses, campaigns, event arrows
3/16 in foam board	Indoor	Stiff but easy to dent	Very light	Easel and table signs	Weddings, events, pricing boards, presentations
1/8 in PVC	Indoor, short-term outdoor	Rigid	Light to medium	Clean wall signs that feel solid	Lobby logos, office signs, menus, wayfinding
.040 aluminum	Indoor and outdoor	Rigid, thin metal	Light	Durable outdoor signs that won't rust	Office hours, parking, rules, safety signs
3 mm ACM	Indoor and outdoor	Very rigid, flat	Medium	Large outdoor signs	Storefronts, building signs, construction project signs
Reflective (corrugated, aluminum, ACM)	Outdoor	Same as the base material	Same as the base material	Signs seen at night in headlights	Driveways, parking lots, roadside and safety signs

Corrugated plastic: the yard sign material

Corrugated plastic yard sign on an H-stake in a front lawn

Light, outdoor, made for short runs

Corrugated plastic has hollow channels inside, like cardboard, but it's plastic, so rain doesn't ruin it. It's the go-to for signs you stake in the ground for weeks or a season.

Slides right onto an H-stake.
Light enough to carry a stack to every corner.
Best for open houses, contractors, campaigns and events.

See sizes in our yard sign size guide.

Foam board and PVC: indoor signs

Foam board wedding welcome sign on an easel in a ballroom

Foam board for events

Our 3/16 in foam board is very light and stands up well on an easel or leaned on a table. It's made for indoor use. It's a smart, low-cost pick for one-day events, but its surface can dent if it's knocked around.

Wedding welcome signs and seating charts
Trade show pricing and QR code boards
Classroom and presentation posters

PVC for signs that feel solid

1/8 in PVC is a rigid plastic board. It's tougher than foam board and has a clean, smooth look, so it suits signs that stay on the wall. It works indoors and for short-term outdoor use.

Lobby and reception logo signs
Office and room signs
Menus and wayfinding signs

See PVC sign printing.

Aluminum and ACM: signs that stay outside

When a sign needs to live outdoors, metal is the safer bet. Our .040 aluminum signs are thin, light and rust-proof, with rounded corners. You can add 4 corner holes so they're easy to screw to a wall or post. They're a good fit for office hours, parking rules and safety notices.

3 mm aluminum composite, often called ACM, is two thin aluminum sheets with a solid core between them. That makes it very rigid and flat, even at larger sizes, and rust-proof. Choose ACM for bigger outdoor signs where you don't want any flex, like a storefront panel or a project sign on a site fence. Learn more on our aluminum sign page.

Large project sign on a construction site fence next to a Hard Hat Area safety sign — Rigid outdoor signs on a job site. See our construction signs page for more.

Reflective options for night visibility

Reflective signs bounce headlight light back toward the driver, so they stand out after dark. We offer reflective versions of corrugated yard signs, .040 aluminum, 3 mm ACM and a plastic A-frame. Pick reflective for driveways, parking lots, roadside directions and any sign people need to find at night.

Real examples: which material we'd pick

Open house weekend

Corrugated yard signs, double-sided, on H-stakes. They go up Saturday morning, come down Sunday night and stack neatly in the trunk for next time.

Dental office hours

A .040 aluminum sign with corner holes, screwed to the brick by the door. It stays outside all year and won't rust.

Wedding welcome sign

A foam board sign on an easel. It's light enough to carry in one hand and only needs to look great for one day indoors.

Job site project sign

A large 3 mm ACM panel on the fence. It stays flat in the wind and holds up for the length of the project.

Still stuck between two materials? Think about three things: where the sign will live, how long it needs to stay up, and whether people will touch or move it. A sign that gets carried around, leaned on or stored between uses does better in a tougher material. A sign that stays put indoors can be lighter and lower cost. And if one job needs a few different signs, you can mix sizes and designs on a single product page with "Add another job," so every design counts toward one bulk price.

How to choose: a quick checklist

Indoor only and short term? Foam board.
Indoor and you want it to feel solid on a wall? PVC.
Outdoor in the ground for a while? Corrugated plastic with H-stakes.
Outdoor on a wall, post or fence for the long haul? .040 aluminum.
Large outdoor sign that has to stay flat? 3 mm ACM.
Seen at night? Choose a reflective version.
Seen from both sides? Order double-sided.

Tip. Not sure which one fits your job? Request a custom sign quote and tell us where the sign will go. Real people check every file and order, and we'll point you in the right direction.

Sign material FAQ

What's the difference between PVC and foam board?

Both are flat boards for indoor signs. Foam board is lighter and lower cost, which makes it great for events. PVC is more rigid and tougher, so it suits signs that stay up on a wall.

Can PVC signs go outside?

PVC works for short-term outdoor use. For signs that need to stay outside, choose .040 aluminum or 3 mm ACM.

Is aluminum or ACM better for outdoor signs?

Both are rust-proof. Aluminum is thin and light, which is ideal for small and medium wall or post signs. ACM is thicker and very rigid, which helps larger signs stay flat.

Are corrugated plastic signs waterproof?

Corrugated plastic handles rain well, which is why it's the standard for yard signs. It's built for temporary outdoor use.

Which sign materials come double-sided?

Yard signs, PVC, foam board and aluminum signs can all be ordered single- or double-sided. Pick double-sided when people see the sign from both directions.

Shop rigid signs Shop yard signs