What is the difference between a mullion and a muntin?
Isabella Ramos
Updated on March 01, 2026
Muntins separate panes of glass, while mullions divide two or more windows or door frames together. They can run both horizontally or vertically.
What are bars in windows called?
A mullion refers to the vertical piece of wood separating the panes of glass, not both the verticals and the horizontal stile pieces. Today, mullions are the vertical bars between the panes of glass in a window.
What is the space between two windows called?
A muntin (US), muntin bar, glazing bar (UK), or sash bar is a strip of wood or metal separating and holding panes of glass in a window. Muntins can be found in doors, windows, and furniture, typically in Western styles of architecture.
What is the meaning of muntin?
Freebase(0.00 / 0 votes)Rate this definition: Muntin. Muntin is a strip of wood or metal separating and holding panes of glass in a window. Muntins are also called “muntin bars”, “glazing bars”, or “sash bars”. Muntins can be found in doors, windows and furniture, typically in western styles of architecture.
What are muntin bars?
Muntin bars (grilles) are bonded to the insulating glass, re-creating the charm of multiple panes. These windows feature between-the-glass blinds, shades and muntin bars or custom-designed, stained glass overlays neatly tucked between panes of glass away from dust, damage and little hands.
What is a muntin window?
Muntin is a strip of wood or metal separating and holding panes of glass in a window. Muntins are also called “muntin bars”, “glazing bars”, or “sash bars”. Muntins can be found in doors, windows and furniture, typically in western styles of architecture.
While they kind of sound the same and are located near each other, muntins and mullions are two different parts of a window. The muntin bars are more like a grille, which divides the window panes into segments.