What is NOT a material commonly used in retail displays?

In the context of retail displays, commonly used materials typically enhance visual appeal and functionality to attract customers and showcase products effectively. Backdrops, lighting, and risers play vital roles in creating an attractive and engaging display. Backdrops can set the scene or theme, lighting enhances visibility and highlights products, and risers help in structuring displays to draw the eye and create depth.

Electric appliances, however, are not generally considered a material for retail displays in the same way that the other options are. They serve more functional purposes rather than acting as display elements. While they may occasionally be a part of a display (such as a television showcasing a brand's campaign), they do not serve the same foundational role as the materials traditionally used to construct the display environment. Therefore, they are not classified as materials in the context of retail displays.