Sign Illumination as a design element is often over looked or over used, and can either improve the effectiveness of the sign, or make it totally unreadable, and ineffective. I will present some basic information that will help the reader understand the relationship between the architectural lighting of a particular project and lighting for signing and graphics in general.
Sign illumination is usually a functional element; it is a practical necessity, which we largely take for granted. Nevertheless, architects and sign designers also use light as a flexible design element. Light from various sources can help define forms and spaces and enhance details. Artificial light when used with some imagination can create psychological moods. Particularly when used with colorful walls, that can create excitement, dramatic emphasis, and emotional warmth.
Important architectural projects are often floodlighted at night. A headquarters office building is part of the corporation's public image, and proper exterior lighting enhances that image. As well as the exterior sign lighting. Existing project lighting used to illuminate signing elements will work, if signs are properly designed, and located to take advantage of it.
There are several basic lighting techniques, which relate to the illumination of exterior signing for architectural projects. These are flood- or spotlighting, ambient lighting, internal lighting, and external lighting. In some situations exterior signs or letters which are cast into the building wall or set flush with it can be illuminated by spill light from existing or supplementary floodlights. This is often an appropriate and subtle way to identify dignified office buildings.
Great care should be taken when floodlighting raised, three-dimensional letters of any thickness because shadows cast from the letters can interfere with legibility. Of course, shadows cast by such letters is a common problem in signing, whether caused by floodlighting or the sun. However, the designer can sometimes overcome these difficult conditions by choosing the right material or finish. For example, aluminum or bronze letters mounted on a dark granite building will be quite legible under varying light conditions, if a bright satin finish is used. The designer must always keep in mind the specific environmental lighting when designing each sign, adjusting the design and lighting where possible to work together.
Major identification signage for some projects are often quite large, and located in such a way that floodlighting should not be used. A"trough" is designed to be recessed next to walkways and covered with a protective glass diffuser. This design provides an unobtrusive source of even illumination, which extends the full length of the sign. Conventional spotlights would have created hot spots, glare, and uneven illumination.
In the form of spill light from existing architectural lighting, ambient lighting may produce adequate illumination for many pedestrian-oriented signs. For example, the address numbers or identification signs at a building entrance can be illuminated by spill light from overhead entrance lighting if colors and materials of these signs contrast well with their backgrounds.
The intensity of ambient light frequently is a critical factor. In parking lots where existing light standards may produce only a few foot-candles of illumination, parking entrance signs usually require internal illumination. Internal lighting of exterior signs is very often necessary to make them legible at night or to give them special emphasis. We make all types of lighted signs, but find that most business's will use lighted channel letter signs with internal lighting as their best choice for effective sign lighting.