Sign materials compared: what to print your sign on

"Sign" covers everything from a foam-board welcome sign at a wedding to a parking lot sign that should outlast the car park. The material is what decides how long it lasts, how it looks and how much it costs. This guide compares the substrates printers offer most, in plain terms, and matches each to the jobs it does best.

Quick comparison

Foam board

Foam board has a polystyrene foam core between paper or plastic faces, usually 3/16 inch or 1/2 inch thick. It is cheap, very light and easy to display on an easel, which is why it is the default for wedding welcome signs, seating charts, presentations and trade-show counters. It dents, warps when damp and is not for outdoor use. For a sign that will be handled or reused, PVC board is sturdier.

Corrugated plastic

The yard-sign material: two polypropylene sheets with vertical ribs between them (flutes). It is waterproof, light and inexpensive. In 4 mm it suits yard signs and short-term outdoor signs; 6 mm and 10 mm are stiffer for larger signs. Strong sun eventually makes it brittle, and it bends in strong wind if unsupported. See our yard sign guide.

PVC board (expanded PVC)

Expanded PVC board, sold under names such as Sintra, is a rigid foam plastic sheet, commonly 3 mm or 6 mm. It takes direct printing well, can be cut into shapes and is smooth and professional-looking. It is excellent indoors (wayfinding, retail displays, menus, office signs). Outdoors it works in sheltered spots but can warp in strong heat, especially in dark colors.

Aluminum

Sheet aluminum (often around .040 or .063 inch thick) doesn't rust, holds up for years and is the material of many parking, property and safety signs. Printed directly or with printed vinyl and laminate, it resists weather well. Corners can be rounded and holes pre-drilled for posts.

Aluminum composite (ACM)

ACM is two thin aluminum skins bonded to a plastic core, commonly 3 mm thick. It is rigid, extremely flat and lighter than solid aluminum of the same stiffness. That flatness makes it the standard for storefront panels, building signs, real estate post signs and directory boards. It can be routed into shapes and mounted with standoffs for a premium look. For permanent building signs, also check local sign permits.

Acrylic

Clear or colored acrylic (often called by brand names such as Plexiglas) gives a premium, glass-like finish for lobby signs, office door signs and displays. It can be printed on the back for a glossy, deep look, cut to shapes and mounted with standoffs. Use UV-stable grades outdoors. It scratches more easily than glass; clean with a soft cloth and acrylic cleaner.

Vinyl banners

Flexible vinyl is the cheapest way to make a big sign and is easy to transport and store. Hemmed and grommeted, it lasts months to a few years outdoors depending on wind and sun. For permanent large signs, frame it or move to ACM. Details: vinyl banner buying guide.

Choosing by job

Inks, laminates and edges

Most rigid signs are printed with UV-cured inks directly onto the board, or with printed adhesive vinyl applied to the board and then laminated. Laminate adds scratch and UV protection and is worth it on outdoor signs expected to last years. Ask about edges: ACM and aluminum edges can be sharp until finished; foam board edges crush easily in transport.

Mounting

• Standoffs: metal spacers that hold a sign off the wall for a floating look. Great for acrylic and ACM.
• Posts and U-channel: for aluminum and ACM outdoor signs; pre-drilled holes help.
• Double-sided mounting tape: for light PVC and foam board on smooth walls indoors.
• Easels: for foam board and PVC at events.
• H-stakes and frames: for corrugated plastic.

Permits and rules

Temporary event signs usually need no permit on your own property, but permanent business signs, large signs and signs near roads often do. Many cities regulate sign size, lighting, placement and how long temporary signs can stay up. Check with your city's planning or permitting office before ordering permanent signage.

Making a sign readable at night

Outdoor signs that must work after dark need a plan for light:

• Reflective vinyl returns headlight light toward drivers, which is why it is used on road and parking signs.
• External lighting such as a gooseneck light or a spotlight on a post works for banners and panels.
• Backlit signs use translucent faces in a lightbox; they are a permanent-sign project and usually need permits and an electrician.
• High contrast matters even more in low light: dark text on a light background, or white text on a dark background.

Questions people ask

What is the most durable outdoor sign material?

Aluminum and aluminum composite (ACM) are the most durable common choices; with good inks and laminate they last for years outdoors.

What is the difference between PVC board and foam board?

Foam board is a foam core with paper or plastic faces: very light, cheap and indoor-only. PVC board is a rigid plastic sheet: sturdier, more water-resistant and suitable for longer use.

What material is best for a wedding welcome sign?

Foam board on an easel is the budget choice; PVC board is sturdier and reusable; acrylic gives a premium, glassy look.

Is corrugated plastic waterproof?

Yes. Corrugated polypropylene is waterproof, which is why it is used for yard signs. Long sun exposure eventually makes it brittle.

What is ACM?

Aluminum composite material: two thin aluminum skins around a plastic core. It is flat, rigid and weatherproof, and is widely used for storefront and building signs.

Sources and further reading

• Aluminium composite panel (ACM)
• Corrugated plastic
• Acrylic (PMMA)

Written and checked by K.R. for UnlimitedBanners.com. Product specs and prices change; confirm details with the printer or seller before you order. Spot an error? Tell us.