External illumination

Mastering Monument Sign Illumination

Since 1985, Matt Charboneau has owned and operated Charboneau Signs in Loveland, Colorado. He is a consultant and designer for monument, channel letter and pylon sign projects. His book, “The Pre-Sale Sign Survey Field Guide - The how-to guide on sign surveys for the professional sign salesperson” can be ordered on his website: www.CharboneauSigns.com or by emailing him at Matt@charboneausigns.com.

Understanding the basic ways to illuminate your monument sign, and how to use your “Free Light,” opens the door to adding eye-catching illumination to your monument sign for very little added cost.

Illumination of a sign can be performed in three distinct ways. From these three methods come a plethora of choices when it comes to illuminating your monument design. Knowing how these choices work together (or fight against each other) is important to recommending the right illumination method for your customer’s monument sign.

A) External Illumination – The method of using light fixtures mounted on the ground or from above that cast light upon the monument structure or the sign faces.

B) Internal Illumination – The process involves installing illumination devices (LEDs, LED Lamps or Florescent Lamps) inside of a sign cabinet or channel letter that sends light outward to the viewer through a variety of sign face, back and return fabrication processes. Proper management of the “Free Light” inside of a sign cabinet can produce creative lighting effects at little to no extra cost. 

C) Passive Illumination – Passive illumination is the use of special reflective materials that do not require a direct power source to make the sign appear as if it’s illuminated at night. When viewed from behind a light source – such as in a car with its headlights on – the material appears to illuminate, although it does not. Light reflects back at the viewer as a result of the materials used to make it.

Now that we have defined the three basic methods of illumination, let’s look at each one to explore the range of possibilities for each.

External Illumination is about the easiest lighting option there is for incorporating illumination into a monument sign design. It can also provide very dynamic visual effects by adding color, mood and visual interest to a sign structure. I call it “Putting Hubcaps on a Cadillac” because of the finished look that that they can give a monument sign. This is the No. 1 under-used method of sign illumination. Exterior fixtures that shine onto the monument sign can add dramatic levels of mood and style by way of using adjustable color changing LEDs. Holidays can be celebrated, and foundations honored by the use of appropriate colors for each event: green for St. Patty’s Day, or pink for Breast Cancer Awareness Month. Fourth of July can be celebrated by using red, white and blue illumination. 

There are basically three ways external illumination can be performed:

Ground Lights – mounted at grade or below the sign and shine up onto the sign face or structure.
Top Lights – attached to the top of the structure or wall that shine down onto the sign.
Recessed Lights – these are built into the sign at hidden locations to provide a glow or illumination of a background or part of the sign that would normally be hidden behind shadows. Think of them as mini-ground lights that are hidden by the monument structure. 

Internal Illumination brings the light source from the outside to the inside of the cabinet. A sign cabinet with florescent lamps and an acrylic face that lights up at night is what most people think of when they are asked what an “electric sign” is.  LEDs (which are quickly replacing florescent lamps) are placed inside of the cabinet and the light floods out the face, through the translucent graphics, and out to the viewer’s eyes. Illuminated cabinets usually have a lot of Free Light inside of them and knowing when to harness that light out the back or sides is a cost effective way to bring more visual interest to your monument signs’ night time presence.

Internal Illumination Face Options

The next area of consideration for illumination is the face of the cabinet sign and how it’s fabricated.

Illuminating the entire area of a 4’x 8’ polycarbonate sign face takes a lot of LEDs but provides a large illuminated image of bright, bold, dynamic translucent print graphics. It really grabs the eye when that much light is projected out to the viewer. However, the amount of LEDs needed can add significantly to the cost of the sign.

If there is only a single line of copy on a sign face, one option to consider is a routed and backed aluminum face fabrication method. LEDs are only required to be placed directly behind the routed text openings, saving considerably on the cost of filling the cabinet with LEDs or using LED Lamps. 

If routed aluminum is a bit of a problem for the budget, try using polycarbonate with block out film. You can offer the same great lighting effect, but with faster and easier installation at a lower cost.

Rather than routing a sheet of 1/8” aluminum for the face, use white or clear polycarbonate along with a blockout film on the background of the face. And just like on a routed aluminum face, it only requires enough LEDs to illuminate the area directly behind the text. The cost of blockout film is much less than routed aluminum, and it provides a pretty convincing “routed/backed” look without the cost and labor of using routed aluminum. 

Don’t waste the “Free Light”

Halo glows are usually “almost free” in most internally illuminated options. If the inside of the cabinet is illuminated, the light being generated can be managed to create this cool effect without a lot of extra cost.

You can add a halo glow to a cabinet (just like you see on a reverse pan channel letter) by doing a little planning up front. If it’s full-face illumination, you will probably have enough free light floating around inside of that cabinet to leak some of it out the back perimeter of the cabinet.

By substituting white or clear polycarbonate for the cabinet’s aluminum back, you provide a way for the light to escape out the back of the sign. This takes a small amount of planning up front. If you use LED lamps, you will not have issues as to where to mount your LEDs. Individual LED modules can be mounted to the polycarbonate back as if it were aluminum. It is usually necessary (especially with clear polycarbonate) to redirect the light back to the face by adding an area of opaque white film to the middle of the polycarbonate back, leaving a 4” wide “transparent white or clear” area around the perimeter of the cabinet back. This is your “Halo Glow Opening.” You can hand cut some 5”-wide strips of translucent color film and apply them to this opening around the edge of the polycarbonate back.

You have now added a halo glow effect, with the option of making the halo a static color of your customer’s choosing. If the halo glow needs some intensity, adding a single row of LEDs behind the halo glow opening will do the trick.

Passive Illumination can add highlights and increase readability for very little cost

Passive illumination can add some dynamic cost-effective illumination to a monument sign quickly and easily. 3M makes a product used by most state highway departments called Scotchlite. It’s available in basic primary colors and is very dynamic when used properly.

The easiest way to demonstrate how adding reflective film can enhance a monument sign is to assume the monument sign has a set of halo lit, reverse pan channel letters on it. As you know, RPC faces do not illuminate and appear dark grey at night. The client likes the clean, neat look of the RPC letter, yet wants the faces to illuminate along with the halo glow at night. One easy option is to add Scotchlite film to the faces of the RPC letters, in the same color that the face and returns are supposed to be. This can be done in two ways. If the face color is white, the use of white Schotchlite makes that choice easy. If it’s a colored letter face such as black, grey, green, blue red or yellow, then one of the primary color films available may work. If the color is unique, white Scotchlite can be digitally printed with translucent UV inks to render the correct color for day and night appearance. 

Note: Before recommending any pressure sensitive film, it’s always advisable to consider the product’s lifespan when exposed to sun and heat conditions for the area you live in. Films are not really optimal for some applications, but you may find that with the right sign design, facing the right direction, and with a client’s understanding that the film will need to be replaced every 4 or 5 years, passive illumination can add significant illumination opportunities for a fraction of the cost of the alternative.

Don’t forget to plan your illumination options

So many times designers and sales people come up with ideas that meet the customer’s needs -- period. They asked for a sign with a face that lights up, and that’s what they got. Sometimes it’s worth the effort to look at a monument sign opportunity and explore all of the hidden options there might be for adding illumination to the structure. In my humble opinion, proper planning from the ground up means starting with external illumination as the core of the sign’s nighttime presentation. It forces you to look at the illuminating cabinets and tenant panels differently, and may push you to try a lighting effect you’ve never tried before.

Don’t forget to test it in the shop

The best advice I can give is to make sure you can light up your sign ideas in your shop, under your control of climate and overhead lighting. Adding or moving LEDs that create halos and faint glows from routed push-through letters are difficult to adjust in the field. Fully assembling and illuminating your sign prior to leaving the shop will ensure that your illumination will look right and work right in the field. 

In conclusion, understanding lighting methods and the tricks and techniques used to manage the light that’s generated is key to successfully planning, designing and selling monument signs that look better and do more at night than during the day. It all starts with the design and grows from there.