International Sign Association (ISA)
1001 North Fairfax Street
Alexandria, VA 22314
Many factors impact the effectiveness of an individual sign. We have identified 5 of the most important: size, sign angle, location, luminance, contrast. This video introduces and explains about these five factors. Additional explanation of the science involved can be found in the technical reports linked below.
Every design choice in the construction of a sign has an impact on visibility, conspicuity, and readability. And every restriction on how a sign is built and where it is located can diminish the visibility and its effectiveness.
ISA supports the application of good design principles to maximize visibility and to create more effective signs. ISA also opposes the imposition of aesthetic regulations on sign design without fully considering the impact of those choices on sign effectiveness.