Iris Schaefer is head of conservation at the Wallraf-Richartz-Museum Fondation Corboud, Cologne. Katja Lewerentz is a member of the academic staff at the CICS (Cologne Institute of Conservation Science), at the University of Applied Sciences in Cologne (FH Köln), and is the curator of various exhibitions. Caroline von Saint-George is a curator and researcher.

Impressionism has probably been given the most attention of any style of art in the last decades. Although it seems as if everything has already been said and shown, this book pursues a new, original path. This book writes the history of impressionism and postimpressionism from a technological perspective—using high-powered microscopes, under infra-red and ultra-violet light—that brings the readers closer to the artists. It examines some of the most famous canvases of the last century, looking for clues as to where the paintings were made, under what conditions and, in some cases, by whom. This book also explores aspects such as how the artists conveyed the quality of light at different times of the day and which conditions inspired them the most, what materials and work methods they used, where the paintings were created as well as their history. The authors have succeeded in conveying their insights in a highly readable way giving us the feeling of being pulled into the daily world of the these painters.