Emphasis is the stress or prominence given to an idea or design element. It is making one idea, color, shape, or texture dominant and others subordinate. If all elements are of equal interest, no one of them will receive attention. Emphasize an element by making it brighter, larger, more textured, surrounded by empty space, point to it with lines, or make it project from the background. A center of interest must be chosen.
Unity is singleness of effect or style, related style, or totality of related parts.
In creating exhibits, unity is a simple matter of repetition and consistency. It is overlapping of identical shapes, the use of any shape, color, line, or texture with a repeat of it elsewhere in the display. It is consistency in lettering also. Each element in the design should mesh with each other so that a single effect is achieved. The challenge in creating a display is determining the visual weight of various design elements.