A piece of horizontal sash, window trim or casing applied to the wall immediately below the window stool; the apron serves to conceal the joint made by the sash or window frame sill and the interior wall surface.

Architrave
Moulding installed high above a window to add grandeur. Architrave moulding also helps disguise miter lines.

Astragal
An interior moulding attached to a pair of doors or sash in order to prevent swing-through. Astragal ensures a tight fit where the doors meet; a flat astragal is one applied to the face of the meeting stile of the door and a T astragal is rabbeted (notched) to the approximate thickness of the swinging door.

Back Band
A narrow, rabbeted (notched) moulding used in conjunction with baseboard moulding and applied to the outside corner and edge of interior window and door casing or along the floor to create a heavy trim look; this increases both the ornamentation as well as the width of the trim.

Band Moulding
A flat, decorative or protective strip that’s flush or raised above the surface; this moulding is similar to a panel moulding as well as an apron profile, and it’s often used to trim mantels or cabinets.

Baseboard
Also called wall base, this moulding is applied around the lower perimeter of the room along a finished floor.

Base Cap
A moulding applied atop a piece of base moulding flush with the wall to create a decorative look. It’s sometimes used with baseboard. Base cap may also be used as a panel moulding or multipurpose profile.

Base Shoe
Also called shoe or floor mould, this narrow moulding provides a transition between finished floors and walls or cabinets; it protects the base from damage and conceals uneven lines or cracks where the base meets the floor. Shoe moulding may be used in place of quarter round.

Bead Moulding
Plain or sprung moulding that’s applied where two surfaces come together at an angle; the profile usually consists of a bead and a cove; it’s often used in place of crown where the walls and the ceiling meet.

Brick Mould
A thick moulding used on an exterior door and/or window as a casing that joins the exterior facing and provides a surface for brick or other siding to butt against. It may be used to form a rabbet for screens, a storm sash or a combination door.

Cased Opening
An interior opening without a door but finished with jambs and casing.

Casing
Moulded or surfaced four-sides (S4S) trim used around door and window openings. Exterior casing trims the exterior of windows and doors. Interior casing trims the interior perimeters of windows and doors.

Caulk
Waterproofing sealant for cracks and joints around window and doorframes.

Chair Rail
Interior moulding applied on the wall about 1/3 of the way up from the floor, paralleling any base or crown moulding, and encircling the room. Originally used to prevent chairs from damaging the walls, it’s now used more for decorative purposes. It can be made from more than one piece of moulding to build up the effect, especially when used in conjunction with wainscoting.

Cope
To cut or shape the end of a piece of moulding so that it will cover and fit the contour of the piece it’s placed against.

Corner Blocks
Square blocks used in place of mitering the side and head casings.

Corner Guards
Use corner guards to protect the outside edges of a wall from damage.

Cove
A moulding with a concave profile used to soften the transition between two planes at right angles to each other. It may be used as a crown around the ceiling or on the inside of a vertical corner as a corner guard.

Crown Moulding
Also called cornice moulding, it is used to cover the intersection where the walls and the ceiling meet – usually over a large angle. Crown moulding is always installed sprung (angled).

Moulding featuring a series of small square blocks uniformly spaced and projecting like teeth.

Dentil Crown
Crown moulding made up of dentil moulding and other moulding types, such as crown and base or base cap, to make up a crown mould system.

Doorjamb
The part of a doorframe that surrounds and contacts the edges of the stiles and top rail of a door.

Finger Jointed
A piece of wood that has a series of fingers machined on the ends of the two pieces to be joined that are meshed together and are held firmly in position by a water-resistant adhesive. These joints are made in a mill used to join short lengths together to make long lengths.

Flat Stock
Boards with either 3 or 4 finished sides for use in shelving, window ledges, base or casing.

Frame
All parts that enclose the window sash or door; vertical members are called side jamb, the top horizontal piece is called the head jamb and the bottom horizontal piece is called the sill.

Full Rounds
Rod-shaped millwork used as closet poles, curtain rods and/or towel bars.

A vertical perimeter frame of a window or door. The most common size for interior use is 1-1/16 inches thick by 4-9/16 inches wide.

Lattice
Thin strips of woven wood, or PVC, surfaced on four sides.

Lineal Foot
One foot of a board or moulding regardless of the width or thickness – also called the running foot; usually this term designates nonspecified lengths.

Miter
An angled cut across the end of a lineal part that’s usually done to join with a similarly cut part at a corner; an end piece cut at an angle other than a right angle.

Moulding
A narrow strip of wood shaped to a curved profile that’s used to accent and emphasize the ornamentation of a structure and to conceal surface or angle joints. Moulding may be exterior or interior.

Mullion
Also called the mull. A mullion is the vertical member of a sash, window or doorframe between openings in a multiple opening frame.

A decorative moulding used to trim out raised-panel wall construction.

Picture Frame Moulding
A narrow moulding along the perimeter of the walls near the ceiling line to support hooks for picture hanging. It can be used to make decorative, formal squares on the wall. Picture moulding is also called picture rail moulding or picture frame moulding.

Plinth Block
A decorative block of wood that is thicker and wider than a door casing and used as part of the door trim at the base to enhance the appearance. Plinth block is also called a base block, foot block or pilaster block.

Plumb
Exactly perpendicular or vertical; at right angles to the floor of a structure.

Primed Moulding
Moulding with a layer of paint or primer applied to it.

PVC
Polyvinyl chloride; a plastic material used to make moulded or extruded parts.

Quarter Round
Moulding that’s 1/4 of a full circle rod and may be used as a base shoe or inside-corner moulding.

Rabbet
A groove cut in or near the edge of a piece of lumber to fit the edge of another piece. This may be a rectangular recess cut or formed along the long edge of a wood part or a cutout along the end or edge of lumber.

Rosette
A decorative wood plaque used at the intersection of two materials, secured to a wall and abutted by the end of a stair rail. It may also be used as ornamental decoration at the bottom of window or doorjambs.

Screen Mould
Traditionally used to hold mesh screening into a wood frame. Also good for edge trim on shelving or as wood trim for wallpaper.

Solid Moulding
Nonfinger jointed moulding.

Square Foot
The length of an item in feet multiplied by its width in feet.

Stool Moulding
A moulded interior trim member serving as a sash or window frame sill cap – these are generally rabbeted.

Stop Moulding
In window trim, a moulding that holds the bottom sash of a double-hung window in place and can also be used as an apron under window stools. In door trim, a stop is nailed to the faces of the doorframe to prevent the door from swinging through the frame.

A lower-interior wall surface that contrasts with the wall surface above it and is generally 3 to 4 feet in height, often with a chair rail added to its top perimeter and a base around its bottom perimeter.

Wainscot Cap
A finishing piece for the top edge of wainscoting. May be used with a chair rail to create a larger profile.

Wall Base
A moulding applied around the perimeter of a room along a finished floor; also called baseboard