Also called artificial marble, stucco marble imitates natural marble or can form completely new colour compositions, such as those which experienced popularity particularly during the Baroque period. The play of colours aimed to increase the illusionistic effect. Due to expensive pigments andthe need for highly specialized professionals, the production of stucco marble was very costly and was long kept a secret; usually the person producing the marble mixed the ingredients behind closed doors or curtains. That is why, today, stucco marble is mainly found in churches and palaces as only the owners and residents of these buildings possessed the necessary wealth to furnish their buildings in such a luxurious fashion.
Stucco marble consists of alabaster plaster, hide glue and pigments; the dyed plaster portions are kneaded together to achieve a marble-like pattern before being pressed into so-called "cakes" and cut into slices, which are then applied on the ground - usually on masonry with lime plaster. Mixing the plaster, as well as applying the slices of stucco marble, requires great technical skill. Numerous further steps are then required to smooth and polish the surface of the stucco marble in order to give the surface its typical gloss and colour intensity.
A particular way of processing stucco marble, which demands advanced artistic skill, is scagliola, a technique of intarsia using stucco marble. It has a similar effect as pietra dura (stone inlay work). Gloss marble is a special form of stucco marble which imitates a white marble surface.
As it is generally the case in monument conservation, when restoring stucco marble, it is necessary to conserve the original substance while, at the same time, restoring the material’s original beauty - in this case its unparalleled gloss and colour. Supplementing missing surfaces poses a particular challenge to restorers; certain skills and talents are required to mix the colours and structures of the materials in such a way that the newly made parts cannot be distinguished from the original.