In the 1630s the Dutch Italianate painter Herman van Swanevelt (ca. 1603-1655) developed in Rome, in collaboration with his colleague and contemporary Claude Lorrain, what in those days was a new type of idyllic ideal landscape whose sunlit 'contrejours' reflected the times of day and which Swanevelt continued to disseminate in the North after he moved to Paris. It was however chiefly his etchings which made this new type of landscape accessible to a large public, and which decisively contributed to the development of the taste for landscape art into the eighteenth century, notably in France. In terms of quality and quantity, Swanevelt was the foremost etcher among the early Italianates. The first of his etchings were made in Rome, probably stimulated by the French etchers Charles Audran, who lived in his house there from 1632 to 1634, and by Claude Lorrain, who made 39 etchings in the 1630s, while most of Swanevelt's - 90 - originated in Paris. The only works he dated are two late series (1653 and 1654). However, during the preparation of Swanevelt's monograph with its critical catalogue of the paintings and drawings, it emerged that the dates of all his authentic, undated designs and prints can be ascertained with a fair degree of accuracy, particularly with the aid of his dated and datable drawings and paintings. Two additional drawings could be established as designs for etchings by Pierre Mariette which were first published after Swanevelt's death, and also four drawings in the Uffizi in Florence, two of them with the visible traces of the etching needle, for four etchings without signature or address. This essay rectifies dates published in A.C. Blume's article of 1994. It makes use of newly found documents, published by M. Szanto in his excellent, substantial article (2003), and facts, published in less accessible literature and providing valuable information pertaining to the biographical background of Swanevelts activity as an etcher during his Paris years. It furthermore combines the familiar signatures, names and addresses of publishers with the critical evaluation of Swanevelt's numerous drawn designs with the nature studies used for this and, for the Paris years, with the new findings in Szanto's monograph. This essay for the first time provides a more exact survey of Swanevelt's development as a draughtsman, the times at which his designs were made and his etchings were printed.