Frey, a prolific painter, devoted much of his work to depicting arid, rocky landscapes occasionally criss-crossed by streams or rivers.
He was aided in this by the numerous studies of rocks that he produced in the course of his lengthy stay in Italy, with its countless landscapes of that kind.
The three studies under discussion here depict three such rocky landscapes.
In the study, the grey of the rocks alternates with brown clumps of earth, dotted here and there with plants despite the seemingly arid terrain. The composition plays entirely on the different hues of grey and brown, broken now and then by small strokes of white lead and green.
It is difficult to tell whether Frey intended these studies to be used in specific compositions, but they are more likely to have been inspirational sketches which he then revisited in various ways for use in one or other landscape painting.