Molding or moulding (see spelling differences) is the process of manufacturing by shaping liquid or pliable raw material using a rigid frame called a mold or matrix.This itself may have been made using a pattern or model of the final object.

A mold or mould is a hoMoldingllowed-out block that is filled with a liquid or pliable material such as plastic, glass, metal, or ceramic raw material.The liquid hardens or sets inside the mold, adopting its shape. A mold is the counterpart to a cast. The very common bi-valve molding process uses two molds, one for each half of the object. Articulated moulds have multiple pieces that come together to form the complete mold, and then disassemble to release the finished casting; they are expensive, but necessary when the casting shape has complex overhangs.[better source needed] Piece-molding uses a number of different molds, each creating a section of a complicated object. This is generally only used for larger and more valuable objects.

A manufacturer who makes molds is called a moldmaker. A release agent is typically used to make removal of the hardened/set substance from the mold easily. Typical uses for molded plastics include molded furniture, molded household goods, molded cases, and structural materials.

Moulding (also spelled molding in the United States though usually not within the industry), also known as coving (United Kingdom, Australia), is a strip of material with various profiles used to cover transitions between surfaces or for decoration. It is traditionally made from solid milled wood or plaster, but may be of plastic or reformed wood. In classical architecture and sculpture, the molding is often carved in marble or other stones.

A "plain" molding has right-angled upper and lower edges. A "sprung" molding has upper and lower edges that bevel towards its rear, allowing mounting between two non-parallel planes (such as a wall and a ceiling), with an open space behind.

At their simplest, moldings hide and help weather seal natural joints produced in the framing process of building a structure. As decorative elements they are a means of applying light- and dark-shaded stripes to a structural object without having to change the material or apply pigments. Depending on their function they may be primarily a means of hiding or weather-sealing a joint, purely decorative, or some combination of the three.

As decorative elements the contrast of dark and light areas gives definition to the object. If a vertical wall is lit at an angle of about 45 degrees above the wall (for example, by the sun) then adding a small overhanging horizontal molding, called a fillet molding, will introduce a dark horizontal shadow below it. Adding a vertical fillet to a horizontal surface will create a light vertical shadow. Graded shadows are possible by using moldings in different shapes: the concave cavetto molding produces a horizontal shadow that is darker at the top and lighter at the bottom; an ovolo (convex) molding makes a shadow that is lighter at the top and darker at the bottom. Other varieties of concave molding are the scotia and congé and other convex moldings the echinus, the torus and the astragal.

Placing an ovolo directly above a cavetto forms a smooth s-shaped curve with vertical ends that is called an ogee or cyma reversa molding. Its shadow appears as a band light at the top and bottom but dark in the interior. Similarly, a cavetto above an ovolo forms an s with horizontal ends, called a cyma or cyma recta. Its shadow shows two dark bands with a light interior.

Together the basic elements and their variants form a decorative vocabulary that can be assembled and rearranged in endless combinations. This vocabulary is at the core of both classical architecture and Gothic architecture.