The exhibition, sponsored by Caja Madrid Foundation, is devoted to the study of the work of Willem Kalf, one of the most significant and influential 17th century Dutch still life painters. On this occasion, the aim is to highlight an aspect of this artist’s work that is not often studied, his technique, together with that of many followers who literally copied his work. With this aim, six works have been brought together, representing both originals and copies, either contemporary or from a later period. The exhibition also presents a selection of the information obtained in the study for the restoration that was carried out before the exhibition, as well as the results of this study. The conclusions of the analysis have been also the subject of several essays included in the catalogue, edited by the curator of the exhibition, Sam Segal, who is a specialist in 17th-century Dutch still life painting, and by Ubaldo Sedano, chief restorer of the Thyssen-Bornemisza Museum.