
Janssen’s prints depict figures, trees, and architectural details rendered light against a dark background, a reverse effect of the typical etching of the period, which reminds our modern eye of a photographic negative. The artist might have been familiar with such a reversal of light and dark through the practice of reverse glass painting, in which he was trained, and indeed, the figures glow with an idiosyncratic solarizing effect, almost as if they are part of a window. The technique was apparently invented by Janssen and is unique in early modern art.