3 Common Types Of Exterior Sign Materials

Exterior storefront signs are an important part of any business, and are the first thing that potential customers will see when passing by outside. There are several different materials that are commonly used for exterior signs, each of which comes with a distinct set of features and drawbacks. Understanding what the various types of exterior sign materials have to offer can help you choose the one that is the best choice for your business.


Aluminum is a lightweight, yet extremely durable material that comes with a couple of unique advantages for outdoor signs. First of all, aluminum is completely immune to rusting, which can help extends its lifespan, especially in seaside areas. Furthermore, aluminum is a malleable material, which means that you can easily mold and customize it, reducing the cost of custom made signs. However, aluminum's flexibility and malleability also give it a few downsides: it is not as durable as other types of metal, and can be easily dented or damaged as a result.

Medium Density Overlay

Medium density overlay (MDO) is made up of plywood, with a resin layer attached to the surface that comes in a wide variety of different colors. MDO signs are much more affordable than aluminum signs are, and can hold up to physical damage without becoming dented or damaged. However, because they have a plywood core, MDO signs are susceptible to water damage, either in the form of warping and twisting over time due to exposure, or mold and mildew growth as water is absorbed into the wood. However, this can be mitigated by treating the edges of the sign with a wood sealant to keep out water, or installing a plastic or metal frame around the sign to keep water out.


Acrylic is a common synthetic material (though signs made out of acrylic are sometimes referred to as Plexiglas) and is completely immune to warping, rusting, and mold growth. Additionally, as acrylic signs are colored all the way through, they do not show wear as easily as other types of painted signs will, which can help extend their lifespan. Since acrylic can also come in varying degrees of transparency, it is possible to have a hollow acrylic sign with lights inside installed, to provide visibility at night. However, acrylic tends to be more expensive than alternative materials used for outdoor signs, which makes it a poor fit for a business with a tight budget.