Stucco is a fine plaster or cement used as a coating for walls or for decoration. It may be used to cover less visually appealing construction materials such as concrete blocks, steel, or adobe. Modern stucco is made of sand, water and Portland cement. Some craftsmen add lime, others consider it improper. Sometimes additives such as acrylics and glass fibers are added to improve the structural properties of the plaster as well as it's workability. This is usually done with what is considered a "one coat" stucco system - as opposed to the traditional 3 coat method. Modern stucco is usually applied over an expanded metal lath that is fastened to the wall sheathing with staples, with a 2 layer moisture barrier in between.

Traditionally, stucco has been used as a sculptural and artistic material. Stucco which is used usually on the outside of the building can be contrasted with lime plaster which is used on the inside. Stucco is hard, whereas lime plaster is soft. For example stucco must be drilled to insert a bolt for attaching another object, while even a thumb tack can be pushed into lime plaster. Even to the finger tips lime plaster has a softness to it which stucco does not have.

Baroque and Rococo architecture makes heavy use of stucco. Examples can be found in churches and palaces, where stucco is mostly used to provide a smooth, decorative transition from walls to ceiling, decorating and giving measure to ceiling surfaces. Stucco is an integral part of the art of belcomposto , the baroque concept that smoothly integrates the three classic arts , architecture, sculpture, and painting.

Since stucco can be used as a decorative means, but also for figurative representation, it provides an ideal transitive link from architectural details to wall paintings such as the typically baroque trompe l'oeil ceilings. Here, the real architecture of the church is visually extended into a heavenly architecture with a depiction of Christ, the Virgin Mary or the Last Judgment at the center. Stucco is being used to form a semi-plastic extension of the real architecture that merges into the painted architecture.

Islamic art makes use of stucco as a decorative means in mosques and palaces. Indian architecture knows stucco as a material for sculpture in an architectural context.

Due to its "aristocratic" look, baroque looking stucco decoration was used frequently in upper-class apartments of the 19th and early 20th century.

It was also employed in the 1950's in pre-molded forms for decorating the joins between walls and ceilings inside houses. It was generally painted the same colour as the ceiling and used in designs where a picture rail or rat rail was in use.