This paper arises from a wider research project focussed on Portuguese gilded altarpieces and sculptures of the Baroque period, which also involved research into contemporary documents and into historical context, as well as into the history of use of materials and practices in gilding technology. It focuses on the results from analyses of historical samples and samples from archaeological reconstructions ofgessoesand gilded surfaces. Analytical and experimental research shed light on diverse aspects of the technology of gilding grounds, such as range and composition of materials within historical objects, methods of production of gilding materials, gilding practices, actual performance of materials and gilded surfaces, and the science underlying the artists’ empirical choice of materials and practices. The documentary research (discussed in Part 1) elucidated the analytical and experimental research presented here, andvice-versa, resulting in a richer and more balanced understanding of thegessoesand of the motives of the people involved in their production. It is hoped that the results will inform future technological studies and conservation decisions. [ABSTRACT FROM AUTHOR]