Which is NOT a principle of visual communication?

Choosing "Form" as the correct answer in this context highlights that it is typically not listed as a core principle of visual communication compared to the other options.

In visual communication, balance refers to the distribution of elements in a design to create a sense of stability. Harmony relates to creating a cohesive look and feel by ensuring that elements work well together, while proximity involves the placement of elements close together to indicate a relationship or to group them effectively.

While form can be an important aspect of visual design, it is more about the shape and structure of individual elements rather than a guiding principle. The other three options directly influence how a message is perceived and understood visually, underscoring their role as fundamental principles in effective visual communication.