Muntin bars are typically aluminum rollformed or extruded profiles available in many shapes and colors, all designed to offer a distinctive look which in many cases attempt to copy the window designs of years gone by.  Muntin Bar or Grill Bar is installed between the panes of glass in a window or door to enhance the appearance of the glass unit and in some cases simulate a divided lite appearance (SDL). The muntin bar can be assembled into various patterns and grid shapes to modify the appearance of the house or building.