Sheet metal is often a preferred material choice for shelves since it offers a flat surface for merchandising products. It is also frequently used for items like header sign holders and graphic shelf channels.
Metal tubing is stronger than wire and is often used for display frames or as structural members of a display. It is generally available in round, square or rectangular shapes and comes in different wall thicknesses depending on the strength required
Wire is a main component used in the retail display world due to its high utility and relative cost effectiveness. It is used to make hooks, shelves, baskets, grids, dump bins, various merchandising accessories, and even entire displays
Wood is commonly used in fabrication of furniture style displays. It's strength vertically and horizontaly make wood paneling ideal for book shelf or cabinet fixtures. Various wood materials available can be painted, or surface and edge band laminated to achieve a certain color or wood grain look.
Plastic is used in many retail displays as a back panel, surface to mount graphics to. It's fairly light weight, available in many colors and can be routered and bent to size. Quite often clear acrylic or PETG is used to create a barrier between consumer and product allowing visibility but not touch.