The space between the two panes of a double- or triple-pane window is called dead-air space.

A deadlite is a piece of glass with a sash around it, but isn't set in the main frame of a window.

With its high water absorbency, desiccant is a material used in glass to absorb water vapor, which causes fogging.

A double-hung window has two operable sashes that open up and down.

Double-strength glass has a thickness of approximately 1/8".

An alternative method of placing glass in a door or window is called dry glazing.

Dual durometer is a vinyl bead material with two different degrees of hardness. The softer part is up against the window and the harder part is inserted into the sash.