The production technology of Italian maiolica: a reassessment

Analytical scanning electron microscopy was used to determine the microstructures and chemical compositions of some fifty Italian maiolica ceramics, together with a della Robbia terracotta panel, spanning the period from 13th to early 17th century AD, and thus establish the changes in the production technology that occurred during this period. The glaze and body compositions of Archaic maiolica (13th–14th centuries AD), as compared to those for contemporary Islamic ceramics, suggest that the production technology for Archaic maiolica could have been introduced into Italy either from Spain or north Africa. The observed microstructures and compositions of the glazes, colorants and bodies of Renaissance maiolica (15th to early 17th centuries AD) are fully consistent with description of its production technology given by Piccolpasso in his treatise, “The Three Books of the Potter's Art”, written in c. 1557 AD. Consideration of the reasons for the use of calcareous clays for the Italian maiolica bodies, the use of lead-alkali glazes, the addition of further sand to the glazing mixture, the variable tin contents of the glazes, and the application of a transparent coperta layer over the painted decoration strongly suggests that these technological choices were made in order to facilitate production and enhance the quality of the final product.