Patience, and shuffle the cards.

—Miguel de Cervantes Saayedra (1547-1616) from Don Quixote

 

Rigid substrates are like a large deck of cards. There are a lot of different cards, but they can be divided into four different suits to simplify their categorization.

 

INDOOR USE

When used for indoor applications, rigid substrates have a different set of desirable qualities than for outdoor applications. 

 

Styrene sheeting is great for indoor work such as  trade show displays.

Temporary—Temporary indoor substrates usually have one big feature—low price. They do not need to be tough, but they do need to be good looking because people can view them close-up. Foamcore and cardstock are the most common items to use here.

 

Permanent—Permanent indoor substrates need a lot of the same features as outdoor substrates. They need to be reasonably waterproof so they can be cleaned. They need to be reasonably fade resistant due to the harsh lighting common in retail environments. And they need to be good looking. Structural composite foams, expanded PVC, particle boards and styrenes are in common use because of their ease of use and reasonable price point.

 

OUTDOOR USE

When used in an indoor setting, rigid substrates should be able to withstand the elements, at least insofar as they need to. 

 

Temporary—Temporary outdoor signs still need to be reasonably weather-proof. Even if they are only used for a day, it might rain or snow that day. And they need to be strong in case it’s a windy day. Corrugated plastic, styrenes and expanded PVC are often used for these purposes. They meet the durability criteria with the added benefit of low cost.

 

Permanent—These substrates are obviously the toughest of the bunch. They need to last a long time under potentially severe conditions—wind, rain, snow, heat, cold, sun and vandalism—for extended periods of time. Plywood, acrylics, polycarbonates, aluminum and plastic composites all work well if used correctly.

 

Sign shops typically carry a wide variety of rigid substrates.

EVERYTHING YOU WANTED TO KNOW ABOUT…

Card Stock—Card stocks are available in a wide variety of thicknesses, from paper-thin to 1/8". They are the easiest product to die-cut and can be power-cut in large stacks. This saves time on large projects and also ensures uniformity. 

 

Foam Board—Paper-based foam board is popular because of its enhanced dimensional stability. Foam boards comprise a very large segment of the lightweight rigid substrate market. They have become the standard for mounting and fabrication in the graphic arts industry. Generally speaking, foam boards are comprised of a rigid foamed polystyrene or polyurethane core with smooth paper layers laminated over the outer faces. 

 

These two vintage products are holding their own against an onslaught of modern competition with a combination of light weight, low cost, and extreme versatility.

 

Corrugated plastics—This material is strong, lightweight, acid free, chemical resistant and outdoor durable. The family includes a wide range of extruded twinwall plastic sheet products produced from a high-impact polypropylene copolymer. In between the twin walls are a series of fluted cells that provide the strength. It is probably the least expensive outdoor substrate made. They are easy to cut, bend and fabricate using only the most rudimentary tools. Many people, however, are put off by its appearance. The extrusion process leaves a regular pattern of indentations along the plastic’s outer surfaces, which is not as attractive as a smooth surface. But don’t let appearances fool you, these are the workhorses of the sign business.

 

Plywood is good for hoardings and other semi-temporary outdoor signage.

Structural Foams—At the top rung of the ladder are the structural foams. These panels are strong, structural, and moisture resistant. They feature exceptionally tough surfaces that resist dents and punctures and are almost impossible to warp or bend. Coverings range from melamine resin-coated paper, to styrene and even wood-fiber veneers. Unlike other lightweight products, thicknesses range from ¼" all the way up to 2". The thickness of the sheets adds extra dimension to the graphics. They also come in 5' x 10' sheet sizes for those oversize projects.

 

Plastic Sheets—Styrene sheets are a major class of rigid substrates. Their main advantage is their low cost, their disadvantage is that most types are not UV durable. They will become brittle and yellow after exposure to the elements. For short term use, however, their value pricing makes them ideal. They are also available in translucent whites and tints that work well for short-term backlit projects like bus ads and trade show graphics. GPS (general purpose styrene) is the least expensive and least durable of the styrene family. HIPS (high-impact styrene) comes in several grades of toughness and durability. ABS (acrylonitrile butadiene styrene) is the toughest of the bunch, and the most UV stable. It also comes in a standard black color that looks beautiful as a backing for hanging graphics.

 

Expanded PVC boards—This category includes products like Sintra have virtually taken over the middle point of the indoor display market. Light, tough, stable and very easy to work with, they also are fire resistant and direct printable. The lack of recyclability is their main downside.

 

Good old-fashioned aluminum sheeting is an ideal substrate for outdoor signage—rigid, durable, non-corroding and weather-proof.

Acrylics—Acrylic sheets are another vintage product that still stands strong. Beautiful, versatile and durable, these rigid sheets come in a large variety of thicknesses and colors. They make very stylish and unique displays.

 

Polycarbonates—This is one of the toughest materials on the market and have excellent impact, heat, cold, staining, UV and chemical resistance. They are very long-term outdoor durable and flame resistant. 

 

Particle Board—Particle board is made from tiny chips of wood or other plant material that are sealed together in a resin to make a very rigid sheet. The sheets are easy to cut and make beautiful edges. The other upside is their low cost, the downside is that they need painting. Environmentally friendly versions are now available as well. They will last a long time indoors, but are not so good in the rain.

 

Plywood—This stuff has been around a long time as well. These strong, durable sheets get their strength from multiple thin layers of wood laminated together with alternating grain direction. The edges don’t look as nice as particle board and they have to be painted, but they are inexpensive and tough as nails outdoors.

 

Aluminum Sheeting—For long-term durability it’s hard to be beat plain old aluminum. It is completely impervious to any form of weather and 100% recyclable- a tough combination to beat.

 

Composite Sheeting—Composite boards are relatively new kids on the block, and have taken on market share rapidly. Employing the light weight and moisture resistance of thermoplastics for the core and thin layers of painted or anodized aluminum for the outer surfaces, they have all of the good points of several products with few downsides (biggest one is their inability to be recycled). 

 

Composite boards are dimensionally stable and weather-proof yet much lighter than solid metal. They are a UL recognized component for electrical signs, have a Class 1 and Class A fire rating and are NCHRP 350 approved for highway and safety signage. Their composite structure gives them excellent strength and rigidity, meaning that less substructure is required during construction. They are easy to fabricate with using ordinary shop and woodworking tools and come pre-painted for a completely hassle-free experience.

 

No matter how you shuffle the deck, there is always a substrate for any use; and there is usually a whole bunch to pick from.  

 

 

Click here to view the Rigid Materials Resources pdf.