Grids, also known as grilles, are optional decorative bars that can be placed in or on a window horizontally and/or vertically to create the appearance of a divided sash. Grids are often customized to create an attractive design or to match the architectural style of a particular home. Colonial, prairie, and diamond grids are three of the most commonly used designs.
Grids are most frequently placed between glass panes, which allows for more permanence and easier cleaning. Other grids can be snapped into place on either the inside or outside of the window.