Despite their similar appearances, the back panel is much stronger than standard cardboard, which generally has just 3 layers. The back panel is actually made of a denser material called paperboard; it only 2mm thick, but not corrugated like cardboard. If a back panel is included in the assembly instructions, it must be used. The back panel adds a significant amount of stability and should be accurately squared with the chassis in order to ensure structural integrity. Failure to do so can lead to several potential problems, including uneven drawers that may not shut properly. For more information on the back panel, click here.