More than just putting up a sign

24 August 2021

Contemporary signs and graphic displays are highlighted by lighting the edge of the acrylic instead of the back.

Contemporary signs and graphic displays are highlighted by lighting the edge of the acrylic instead of the back.

By Jane Nash

As the world begins to emerge from the COVID-19 pandemic, the trillions of dollars of stimulus money pumped into the economy are driving an unprecedented surge in retail spending. The National Retail Federation (NRF) projects some $4.33 trillion in spending in 2021, much of which is predicted to be in-store, as a public weary of staying home seeks out once-familiar shopping experiences.1

To meet the rush, retailers have invested heavily in features to attract shoppers and enhance the shopping experience. Most of the attention has centred on technology innovation and adoption, but the customer experience is about more than click-through rates and leveraging smartphone capabilities.

Technology is one piece of the in-store customer experience, but another significant part is walking through a store and browsing. One of the most critical aspects of curating a positive in-store experience is choosing the right thermoplastic sign to draw customers in and, when inside, guide them with noticeable point-of-purchase and product displays.

Polycarbonate or acrylic?

The first step is to choose the best sign material for the project at hand. Before selecting what type of panels to use or debating between light-emitting diodes (LEDs) or fluorescent bulbs, one should choose the substrate that works best for the business’s sign. When it comes to lighted sign panels, the choice is between a polycarbonate and a high-impact acrylic (also called impact-modified acrylic [IMA]). The more information retailers have about each option, the better able they are to make qualified, informed decisions.

Sign-grade acrylic[1] is impact resistant, durable, versatile, flexible, and suitable for cutting, bending, drilling, and gluing. All these features make it an excellent choice for evolving retail environments. There are different types of acrylics with various characteristics able to meet the needs of specific applications.

Cast sheet is manufactured using a method known as the cell cast process, while extruded sheet is manufactured using a process known as continuous manufacturing. In the cell cast process, a casting liquid is poured between two plates (usually glass), which have a gasket between them to form a cell or contain the casting liquid. Then, the resin solidifies, usually through polymerization or crosslinking.

Cell cast acrylic sheet has excellent optical qualities and resists crazing (tiny cracks that can form on the surface of some thermoplastics). This makes it a popular choice for cosmetics counters because the chemicals in perfumes, colognes, and lotions can find their way into cracks and degrade surfaces over time. Cell cast delivers an elegant look, accentuating the value of premium products such as jewellery and cosmetics.

Continuous casting is a production form for manufacturing acrylic sheet. The process involves pouring partially polymerized acrylic between two highly polished stainless steel belts.

Continuous cast is an excellent choice for point-of-purchase displays, interior and exterior signs, skylights, and countless other retail applications.

Continuous cast is an excellent choice for point-of-purchase displays, interior and exterior signs, skylights, and countless other retail applications.

The most versatile acrylic with the broadest range of uses is continuous cast. It is strong and lightweight, with good optical clarity and substantial craze resistance. Further, it is available in larger sizes, whereas cell cast is limited by the size of the glass used to make it. Continuous cast is an excellent choice for point-of-purchase displays, interior and exterior signs, skylights, and countless other retail applications. It works well with back and edge lighting, including LED lights, because of its light transmission and diffusion properties. It is also worth noting clear, continuous cast acrylic is approved by the U.S. Food and Drug Administration (FDA[2]) for food contact.2 Thus, it is a strong option for use in grocery store produce displays, food bins, and countertops.

Extruded acrylic is flexible, suitable for bending and fabricating, and available in large sizes. However, it lacks the pristine optical clarity of cell cast or continuous cast acrylic and is susceptible to crazing when not cleaned properly. Continuous cast and extruded acrylic are sensible choices for point-of-purchase displays that are changed and updated frequently—for example, end-cap displays in a retail store or displays commonly seen in convenience stores. Additionally, cell cast and continuous cast have a higher resistance to chemical attack due to their higher molecular weight, while extruded acrylic is a softer material.

Impact-modified extruded acrylic is optically clear and delivers fabrication flexibility, with superior impact resistance compared to cell or continuous cast. This sheet product is appropriate for some of the same applications as polycarbonate. However, the two materials are not the same and have some notably different performance characteristics.

Both acrylic and polycarbonate are classified as thermoplastics—a plastic material that becomes pliable above a specific temperature, then solidifies when it cools. Which plastic a sign shop selects depends on a few factors, including the application, sign type, and what is specified for the project.

The challenge lies in addressing the needs of a given sign project while still providing the best value for the customer. For example, acrylic has the highest gloss of any thermoplastic. For signs requiring high gloss and forming letters or images, acrylic is somewhat better than polycarbonate.

Polycarbonate sheet is a more robust material than acrylic and is considered virtually unbreakable. Relative to acrylic, polycarbonate offers greater heat resistance, higher impact strength, enhanced ultraviolet (UV) resistance, and increased resistance to breakage. Additionally, there are numerous other considerations to review before choosing a substrate.

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Impact strength

Polycarbonate has up to 30 times the impact strength of acrylic. Although acrylic is high impact, polycarbonate is extremely resistant to breakage. Polycarbonate is often used in bullet-resistant applications due its superior impact strength.


Polycarbonate may offer better panel strength and higher wind load ratings than acrylic, meaning it can withstand the forces of wind better. However, acrylic and polycarbonate can both withstand high winds and both have excellent long-term weatherability characteristics. Depending on the application and project requirements, one may be preferred over the other.

If considering signage in areas prone to hurricane-force winds, polycarbonate at 3 mm (0.118 in.) and greater is rated under Miami-Dade for use in high-velocity hurricane zones. Smaller signs of 914 mm (36 in.) or less would likely use acrylic. Where a trim cap is being used, acrylic is the preferred substrate because acrylic glues much more easily than polycarbonate.

For large signs where forming is required and there are no drying capabilities, or for formed signs requiring a higher degree of definition on the corners and edges, high-impact acrylic is recommended.


Contemporary signs and graphic displays are highlighted by lighting the edge of the acrylic instead of the back.

In addition to the impact resistance of IMA, another benefit of acrylic is a sleek, glossy exterior, as mentioned. The exterior shine on the finish of a high-impact acrylic lighted sign panel can be a significant selling point for business owners. Acrylic display colours are better than those seen with polycarbonate and offer better clarity in the sign design. Standard polycarbonate will yellow in exterior applications unless customers are ordering a type of polycarbonate with a co-extruded UV-blocking capped layer. This layer provides a high level of UV absorption to the polycarbonate sheet, extending weathering performance.

Design creativity and innovation

Another esthetic point to be aware of is glare and the use of edge-lit products. Edge-lit material comprised of continuous cast acrylic has illuminated particles infused throughout the sheet, forcing light out. In many instances, this is used to diffuse LED lighting. An example is retail signage using edge-lit material with a graphic on top for promotional purposes. Such illuminated signs can employ a one- or two-sided design, and may be useful in applications such as illuminated wraparound counters, exit signs, and other wayfinding/directional supports.

Another example, used by cosmetic retailers to entice customers and showcase their logos or brand names, is block lettering. These are solid sheets that can be up to 30-mm (1 1/8-in.) thick and can be used as a standalone design or as push-through letters. Many major brands use large block letters, inserting LEDs in the back of each letter without a metal outline to offer an elegant look.

For a sophisticated lighting effect, another design option is to employ continuous cast material with a frost effect incorporated throughout. This frost effect will not wash out during the fabrication or forming process and offers an elegant, soft look for displays, wall partitions, and dividers.


There are solid advantages to selecting cell cast, continuous cast, extruded, and high-impact acrylic, as well as polycarbonate. These plastics are exceptionally durable and will last for many years, while still maintaining their pleasing appearance. The final decision is a matter of preference, manufacturing capabilities, and what is most important in the application.

Retail signage is one of the first and last things customers see when they visit a store. It is crucial to ensure the right solution is selected for the long term. Whether employing polycarbonate or acrylic, retailers can be confident the result will be the perfect lighted sign to meet their business needs.

Jane Nash, Tennessee sales manager/specification specialist for Plaskolite, has been in the acrylic manufacturing industry for more than 40 years. She joined Plaskolite in 2018 as part of the Lucite acquisition and is actively involved with sales and specifications, working with architects and the design community. Nash is active with several organizations, including the Society of Experiential Graphic Design (SEGD), American Institute of Architects (AIA), Screen Printing and Graphic Imaging Association (SGIA), ISA, and the Mid South Sign Association (MSSA). She can be reached via e-mail at


1 For more information, visit

2 In 2016, an agreement was signed between the U.S. Food and Drug Administration (FDA) and Canadian Food Inspection Agency (CFIA) recognizing each other’s food safety systems as comparable to one another.

  1. Sign-grade acrylic:
  2. FDA:
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