Glossary of Terms

Glossary of Infinity® from Marvin window and door terms

Active Panel - Primary operating door panel.


Apron - A piece of casing or decorative trim installed against the wall immediately beneath the stool of a window.

Argon Gas - A colorless and odorless gas used to fill the airspace between insulating Low E glass. The addition of argon dramatically increases the insulating performance of the Low E glass.

Assembly - Single units mulled together.

Astragal - A moulding applied to one stile of a French Door, Sliding French Door or French Casement window unit which the other door panel or window sash strikes. Usually, head and foot bolt devices will be found on the astragal side.

Authentic Divided Lites (ADL) - Also known as True Divided Lite. Permanent stationary muntins and bars separate the glass in a window or door sash to give the sash two or more lites of glass.


Balances - A block and tackle system used in the jamb liner of double hung or single hung units.




Bow Windows - A series of adjoining window units, installed on a radius.

Brick Mould Casing BMC - An exterior moulding of window and door frames that abuts the exterior facing material of the structure. The casing serves as the boundary moulding for brick or other siding material and also helps to form a rabbet for screens and storm sash or a combination door.



Capillary Tubes - A tube inserted into the insulating glass spacer that allows the inside and outside air pressure to equalize in higher elevations.

Casemaster - A Marvin Window trade name used in the past for their casement window.

Casement Window - A combination of frame, sash, weather-strip, concealed hinges and operating device assembled as a complete and properly operating unit. Casements have a flat sill and a sub-sill; screens and energy panels are optional. Operating casements have a crank handle for smooth operation.

Clad Brick Mould Casing (BMC) - A clad extrusion designed to simulate brick mould casing for Marvin clad products.

Cladding - Marvin clad products refer to wood window and door parts which are covered with an extruded permanent colored aluminum jacket on the exterior side of the frame and sash.


Cottage Window - A window with unequal sash, top, and bottom.

Daylight Opening (DLO) - The width and the height of the visible glass.

The depth of the Jamb - The point where the exterior casing ends to the point where the interior casing begins. On clad units, the point from the backside of the nailing fin to the interior of the frame.

Direct Glaze - Refers to a window with no sash. The glass is glazed directly into the frame and is stationary.

Divided Lites - Division of light by the use of muntin bars.

Muntins - The actual bars that create a pattern in the window.

Authentic Divided Lites (ADLs) - Single or insulating glass, individually glazed between the muntin bars.

Simulated Divided Lites (SDLs) - Muntins permanently adhered to the interior and exterior of the glass.


Spacer Bar - Tiny aluminum bars inserted between SDL muntins to emulate ADL.

Grilles Between Glass (GBG's) - Aluminum flat or contour bars divide the glass visually. Because the grille is between the glass, grilles do not become misplaced or damaged. Cleaning is easy without small panes of individual lites. More about divided lites.

Double Hung - Double hung windows have two movable sashes which operate vertically. Double hung sashes are held in an open position with the use of coil spring block and tackle balancing devices.



Electric Operator - An electrically operated device which will open casements or awnings units by using a switch. This is used instead of a roto gear crank or pole crank.

Energy Panel (EP) - Formerly called an RDG - removable double glazing is a piece of glass annealed or tempered and finished on the edges by a surround. EPs are applied to windows or doors and rest on the glazing stop. EPs offer the homeowner added energy efficiency.

Escutcheon - A decorative door handle plate attached to the stile directly behind the handle(s). Generally square or rectangular shaped.

Espagnolette - Tilt-Turn hardware which houses the gear mechanism for the Tilt-Turn, inswinging casement and hopper handle.






Frame Expander - A flat aluminum extrusion used in conjunction with the 90-degree frame expander to provide a flat casing appearance for clad units.

French Casement - A casement styled unit with two sashes in one frame providing a sense of openness unrestricted by a vertical mullion or stiles when both sashes are open.

French Door - Marvin French Doors are available in either inswinging or outswinging rectangular or arch top style choices.

Friction Limiter - A device used on a Magnum Tilt-Turn to provide friction to the sash when in the swing position.

Glass Size (GS) - The measurement of the actual glass, not the visible glass.

Glazing - Installing glass into windows and doors.

SINGLE GLASS - Glazing with a single piece of glass.

INSULATING GLASS - two panes of glass separated by a spacer and hermetically sealed together with dead air space between the panes.

Glazing Tape - A two-sided adhesive tape placed between the glass rabbet and the glass and/or the glazing bead and glass of some unit types.

Glider - Horizontal operating units which have one sash fixed while the other glides open and shut horizontally.


Handing - A term used to describe the right or left-hand operation of a window or door.

Head Jamb - The top member of a frame.


Historical - A term used to define a window or door product meeting the requirements of historical renovation standards.

Inactive Panel - Secondary operating door panel.

Insulating Glass (IG) - See Glazing.

Inswing French Door - A French door with panels that swing to the inside. One, two, three and four-panel units available as stationary or operating.

Inswinging Casement - A non-tilting version of the Magnum Tilt-Turn.


Jamb Extension - A jamb-like member usually surfaced on four sides, which increases or extends the depth of the exterior or interior window or door frame; jamb extensions imply a larger depth than "wood jamb liners."

Jamb Liner - Thin strips of wood attached to the head jamb, side jambs, and sill to accommodate various wall thicknesses. Common jamb depths are: 4 9/16", 4 13/16", 5 1/16" and 5 3/16".

Keyed Cylinder Lock - A lock providing an exterior entry and locking convenience.

Krypton Gas - Inert gas is known for its ability to provide insulating properties in a small airspace.

Laminated Glass - Glass composed of two sheets of glass fused together with a sheet of transparent plastic between the sheets. When broken laminated glass will not leave the opening.


Lever Lock - A lever handle and lever arm operator available as an option on awning units.


Low E Glass - Low E stands for low emissivity. The lower the emissivity, the higher the percentage of long-wave radiation blocked thereby improving thermal performance. Low E glass is coated with a thin microscopic, virtually invisible, metal or metallic oxide layer. The primary function is to reduce the U-value by suppressing radiative heat flow. A secondary feature is the blocking of shortwave radiation to impede heat gain. There are two basic types of Low E glass. The first, vacuum or sputter coated Low E, is referred to as soft-coat (See Low E II definition). The second is pyrolytic Low E, commonly referred to as hard-coat. (See pyrolytic definition.)


Magnum - A Marvin trade name for heavily constructed window products which are designed for applications where a heavy-duty product is necessary.

Magnum Double Hung - A heavy duty double hung product made with larger than standard parts. The larger sash parts will accommodate larger glass sizes.

Magnum Hopper - A heavy duty window designed to tilt into the room for ventilation purposes.

Magnum Tilt-Turn - A heavy duty window. The Magnum Tilt-Turn has hardware which allows the sash to either be tilted into the room for ventilation or swing into the room for egress or cleaning.

Masonry Opening - A brick, stone or block opening into which a window or door unit is installed including the outside casing.

Mortise and Tenoning - The system by which Marvin assembles authentic divided lite units, a projecting tenon on either the muntins or bars fit snugly into a mortise in either a bar, stile or rail.


Mullion - The vertical member of a sash, window or door frame between openings in multiple opening frames.

SPACE MULL - Two or more units mulled together with a space left between the units. The jamb extension surrounds the entire unit.


Mullion Cover - A clad cover for space mull usage on the Clad Magnum Double Hung Replacement System with Panning. It covers a range from 3' minimum to 10'

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