Used to describe parts of a building's windows, not just any vertical bar.

Architectural Feature

Mullions visually break up large glass areas, making windows more interesting.

Visual Separation

Mullions can also provide structural support to windows.

Mullions are common in historical buildings and give a traditional look.

Mullions are made from various materials, such as wood, stone, or metal.

In screens and windows, mullions can be key elements of the overall design.