Which design principle involves the relationship between opposing elements?

The design principle that involves the relationship between opposing elements is contrast. Contrast is crucial in design as it helps to create visual interest and draw attention to specific areas of a composition. By placing elements that differ in color, size, shape, or texture next to each other, a designer can highlight the differences, making both elements stand out more effectively. This technique can be used to create focal points and to guide the viewer’s eye through the design.

For instance, using a bold, dark color against a light background creates a strong visual contrast that can make text more legible or an image more striking. By understanding and effectively utilizing contrast, designers can create more dynamic and engaging designs that capture the viewer's attention. Thus, contrast serves as a vital tool in structured visual communication, ensuring that the elements interact in a way that conveys the intended message clearly and effectively.