Molding or moulding is a strip of material with various cross sections used to cover transitions between surfaces or for decoration. It is traditionally made from solid milled wood or plaster but may be made from plastic or reformed wood.
A "sprung" molding is a strip that has beveled edges, allowing it to be mounted at an angle between two non-parallel planes (such as between a wall and a ceiling). Other types of molding are referred to as "plain".
At their simplest, moldings are a means of applying light and dark shaded stripes to a structure or object without having to change the material or apply pigment. The aesthetic function is similar to that of go-faster stripes applied to the side of a vehicle.
Imagine a flat vertical wall evenly lit by daylight. Adding a small overhanging horizontal step will introduce a dark horizontal band — this is called a fillet molding. Conversely, adding a vertical fillet to a horizontal surface will appear as a light band.
These bands do not need to be evenly shaded. A concave cavetto molding will produce a band which is darker at the top and lighter at the bottom, whereas a convex ovolo molding will be lighter at the top and darker at the bottom (other concave moldings are the scotia and congé, and other convex moldings are the echinus, torus and astragal).
Placing an ovolo molding directly above a cavetto forms a smooth 'S' shaped curve with vertical ends, which appears as a band that is light at the top and bottom but dark in the interior — this is called an ogee or cyma reversa molding.
Similarly, a cavetto above an ovolo forms an 'S' with horizontal ends and appears as a dark band with a light interior — called a cyma or cyma recta molding.
Together, these basic elements and their variants form a decorative vocabulary which can be assembled and rearranged in endless combinations. This vocabulary is at the core of both Classical architecture and Gothic architecture.
Molding from the Table of architecture of the 1728 CyclopediaThere are a variety of common moldings:
Astragal — attached to one of a pair of doors to cover the air gap between, expecially, fire doors.
Baguette — Thin round molding, smaller than an astragal, sometimes carved, and enriched with foliages, pearls, ribbands, laurels, etc. When enriched with ornaments, it was also called chapelet.
Bandelet — Any little band or flat molding, which crowns a Doric architrave. It is also called a tenia.
Baseboard, "base molding" or "skirting board" — used at the junction of an interior wall and floor to protect the wall from impacts.
Batten — a symmetrical molding that is placed across a joint where two parallel panels or boards meet
Beading is another term for a molding that is used at the junction of an interior wall and ceiling
Beak — Small fillet molding left on the edge of a larmier, which forms a canal, and makes a kind of pendant.
Bed molding — a narrow molding used at the junction of a wall and ceiling. Bed moldings can be either sprung or plain.
Cable molding — Convex molding carved in imitation of a rope or cord, and used to decorate the molding (decorative) decorative moldings of the Romanesque style in England, France and Spain. The word cabling by itself indicates a convex circular molding sunk in the concave fluting of a classic column, and rising about one-third of the height of the shaft.
Cabled fluting — Flutes filled up with pieces in the form of cables.
Casing — the trim for both sides of a door or window opening.
Cavetto — Hollow, concave molding sometimes employed in the place of the cymatium of a cornice, as in. that of the Done order of the theatre of Marcellus. It forms the crowning feature of the Egyptian temples, and took the place of the cymatium in many of the Etruscan temples.
Chair rails — a horizontal molding placed part way up a wall to protect the surface from chairs. Primarily used now for decoration.
Chin-beak — molding exactly like a quarter-round, except that its situation is inverted. There are few examples of this in ancient buildings, but is common in more recent times.
Corner guard — a molding used to protect the edge of the wall at an outside corner, or to cover a joint on an inside corner.
Cove molding — a concave-profile molding that is used at the junction of an interior wall and ceiling.
Crown molding — a wide, sprung molding that is used at the junction of an interior wall and ceiling.
Cyma — molding of double curvature, concave at one end, convex at the other. When the concave part is uppermost, it is called a cyma recta but if the convex portion is at the top, it is called a cyma reverse, When the crowning molding at the entablature is of the cyma form, it is called a cymatium.
Drip cap — this is placed over a door or window opening to prevent water from flowing under the siding or across the glass.
Fillet — small, flat band separating two surfaces, or between the flutes of a column
Godroon or Gadroon — Ornamental band with the appearance of beading or reeding, especially frequent in silverwork and molding. It comes from the Latin word Guttus, meaning flask. It is said to be derived from raised work on linen, applied in France to varieties of the, bead and reel, in which the bead is often carved with ornament. In England the term is constantly used by auctioneers to describe the raised convex decorations under the bowl of stone or terracotta vases. The godroons radiate from the vertical support of the vase and rise half-way up the bowl.
Keel molding — with a sharp edge, resembling in cross-section the keel of a ship. It is common in the Early English and Decorated styles.
Screen molding — this is a small molding that is used to hide the area where a screen is attached to the frame.
Shoe molding, toe molding or quarter-round — often used at the bottom of the baseboard to cover a small gap or uneven edge between the flooring and the baseboard.