What is the minimum letter height required for 'No Smoking' placards?

• A. 2 inches
• B. 3 inches
• C. 4 inches
• D. 5 inches

Answer: (B)

The minimum letter height required for 'No Smoking' placards is established to ensure visibility and legibility, especially in environments like airports where safety and compliance are critical. A letter height of 3 inches is deemed sufficient because it allows for clear recognition from a distance, making it easy for individuals to understand the message quickly. This size is crucial in promoting safety and compliance in areas where smoking is prohibited. The height is standardized to maintain consistency and effectiveness in communication throughout the facility.

Using larger lettering, while potentially beneficial in some contexts, is not necessary for effective visibility in this specific application, and smaller lettering would not provide the same level of clarity and warning needed in high-traffic areas such as an airport. Thus, 3 inches strikes an effective balance between visibility and practicality.