There are numerous studies on 18th century Russian icon painting. This article discusses the findings of A. N. Loujetskaia, M. N. Moleva, and E. Belioutine. They describe the grounds and pigmented layers of several dozen works. The composition of the layers of paint does not change in the whole of the eighteenth century: they are applied in three successive stages--one underlying colored layer, the drawing of the outlines, and the surface layer with glazes and varnishes. It is the ground which has changed most. At the beginning of the 18th century it was formed with one colored layer; in the second half of the 18th century we find two layers. When there was only one layer it was more red, when two, the lower layer also tended to be red, and the top layer clear to white. Often the only criterium for dating the paintings is the nature of the ground. The authors examined several dozen icons and describe the grounds and colored layers used.