Muntin
Also known as a grille, a muntin is a thin strip of wood, metal or plastic used to divide window panes to coordinated areas. In many contemporary plastic or metal double-paned windows, vinyl or metal muntins are positioned between two big solid sheets of glass or panes. Older windows comprise wood muntins which possess an attractive stepped profile that produces an architectural look, in addition to their own functioning as window dividers. Those running vertically are referred to as lengthy muntins; those running horizontally and linking to the extended muntins are referred to as cross muntins.
Chris Hill
This case shows three cross muntins for each sash and two extended muntins.
Gander Builders
Muntins can be highly detailed and finished in many different ways.
Carter Kay Interiors
Or muntins can be quite simple to create clean lines.