Selecting the right substrate, or material, is one of the most important steps in producing a successful sign or mounted graphic. The material you choose affects the look, durability, installation method, weight, cost, and overall impact of your project. Before choosing a substrate, consider:
Where will the piece be displayed? Indoors, outdoors, or both?
How long does it need to last? Hours, weeks, seasons, or multiple years?
How will it be installed or handled? Mounted to a wall? Carried often? Hung from a ceiling? Exposed to wind and sun?
What type of finish do you want? Matte, glossy, smooth, textured, or transparent?
What is the budget and expected reuse? Some materials are economical but short-term; others are premium and long-lasting.
With these considerations in mind, the guide below outlines the most common rigid substrates used in large-format printing, including typical thicknesses, durability notes, and recommended indoor or outdoor applications.
Foam Core
Common thicknesses: 3/16″, ½″
Lightweight, smooth, and easy to cut. Ideal for mounted posters, indoor presentations, event displays, easel-back signs, and temporary messaging. Foam Core is cost-effective and easy to hang, but not designed for high-traffic environments.
Best used: Indoor only
Gator Board / Ultraboard
Common thicknesses: 3/16″, ½″, 1″
A more durable alternative to Foam Core with a dense foam interior and rigid veneer surfaces. Resists warping and denting, making it excellent for long-term indoor displays, photo mounting, retail signage, and reusable presentation boards.
Available with either white or black core in most thicknesses.
Best used: Indoor (can be used briefly outdoors but not recommended for prolonged exposure)
Polystyrene
Common thicknesses: .020″, .040″, .060″
Commonly referred to as "styrene," this is a smooth, durable plastic that’s flexible yet rigid enough for professional signage. Ideal for POP displays, menu boards, shelf talkers, retail signs, and hanging graphics.
Best used: Indoor (short-term outdoor use possible in mild conditions)
PVC
Common thicknesses: 1 mm (~0.04″), 3 mm (~1/8″), 6 mm (~¼″), 10 mm (~3/8″)
A strong, lightweight PVC foam board with excellent print quality. Suitable for both indoor and outdoor applications including wall panels, trade show displays, retail graphics, and semi-permanent signage. Commonly referred to with the brand name Sintra.
Best used: Indoor and Outdoor (short-term only)
Corrugated Plastic / Coroplast
Common thicknesses: 4 mm, 6 mm, 10 mm
Lightweight, economical, and weather-resistant corrugated polypropylene. Common for yard signs, event signage, campus directional signs, real estate signs, and short-term outdoor promotions. Most common thickness for yard signs is 4mm.
Best used: Outdoor (excellent outdoors; also suitable for temporary indoor signage)
Aluminum Composite Material (ACM)
Common thicknesses: 3 mm (~1/8″), 6 mm (~¼″)
Two aluminum sheets bonded to a polyethylene core provide outstanding rigidity, dimensional stability, and weather resistance. Ideal for exterior signs, building identification, wayfinding, long-term installations, and premium displays requiring a professional finish. Available in white, black, brushed gold, or brushed chrome finish. May be referred to using brand names Max-Metal or Dibond.
Best used: Outdoor and Indoor (excellent in all environments)
Rigid Paperboard / ImageMax
Common thicknesses: 24 pt (~0.024″), 30 pt (~0.030″)
A recyclable, paper-based rigid board ideal for indoor signage, posters, POP displays, and sustainable projects. Lightweight and eco-friendly, with excellent print quality—but not suited for moisture or extended handling.
Best used: Indoor only
Acrylic / Polycarbonate
Common thicknesses: 1/8″, 3/16″, ¼″, ½″
A premium, glass-like substrate with exceptional clarity and a polished finish. Perfect for photo mounting, interior décor, illuminated signs, office signs, and architectural panels. It’s durable but can be heavy and requires proper installation hardware. Common applications include "second surface" printing, where the image is printed in reverse on the back of the acrylic sheet, providing dimension to your finished artwork.
Similar in appearance to acrylic, polycarbonate is an extremely durable, impact-resistant substrate. With superior toughness, polycarbonate is used for protective panels, exterior signage in harsh conditions, industrial environments, and applications requiring high strength or shatter resistance.
Best used: Indoor (can be used outdoors with care, but UV and impact exposure reduce lifespan)
Sign Grade Aluminum
Common thicknesses: .040″, .063″, .080″
Solid aluminum sheet designed for long-term exterior use. Rust-proof and weather-resistant, ideal for regulatory signage, street and parking signs, directional signs, and campus or municipal installations.
Best used: Outdoor (also appropriate for long-term indoor installations)
To learn more about signage and display graphics, or to request a specialty material, email Printing Services at printingservices@vanderbilt.edu or call 615-936-4544.