204. Plastering may be described as a process of clothing the structural members, which compose the skeleton of the building fabric, with plastic material so as to render it more agreeable and habitable. This process is applicable to both the exterior and the interior of the structure. When used for exterior work, as in overlaying an inferior grade of stone or brick masonry, or in forming the covering material or wall sheathing to protect the framework, it is usually classified as stucco work.

Improved processes in the manufacture of brick and terra cotta, increased facilities for handling and cutting stone, and the desire for truthful construction, have all acted to drive stucco work out of the field; so strongly has this reaction influenced the public mind that the term stucco has become synonymous with everything that partakes of a spurious construction and fraudulent concealment. This change in public taste has practically limited the exercise of the plasterer's art to interior work. In this restricted sphere, however, there is ample opportunity for the exercise of good, honest, and skilful work, as no other substance has yet been produced which so well satisfies the requirements in the treatment of the large areas which occur in interiors.

The natural march of progress, and especially the introduction of modern fireproof construction, has led to the development of new methods and the improvement of old ones, so that at present the art of plastering has reached a high degree of perfection. To obtain such results, the prime requisites are good materials and workmanship. As these depend greatly upon the specifications, it is necessary that the architect be well acquainted with the nature and qualities of the materials, and the proper methods of performing the work, in order to be able to intelligently make such specifications, and to see that they are properly carried into execution.