Metal sheets: galvanized steel sheet (most commonly used), ordinary thin steel sheet, stainless steel sheet, aluminum and aluminum alloy sheet, and plastic‑composite steel sheet (such as PVC‑laminated steel sheet).

　　Non-metallic panels: rigid polyvinyl chloride (PVC) sheets, fiberglass-reinforced plastic (FRP) sheets, and inorganic glass–magnesium composite panels.

　　Composite panels: color‑steel sandwich panels (e.g., with polyurethane or rock wool cores), and aluminum‑foil composite insulation panels (commonly used in flexible ductwork or thermal insulation systems).