To record the delicate shadows of plants, Susan Purdy arranges selected elements over the top of photographic paper, and the paper is exposed to light.  It is then developed, fixed and washed.  The resulting prints have a dark background and a silhouette of the objects in white. Conceptually the photogram differs fundamentally from lens-based photography as a kind of light imprint! By its immediacy, its quality of reversed tones, the photogram is a cousin to printmaking techniques and shadow phenomena. It is a simple and direct kind of camera less photography explained by Dr Isobel Crombie in her catalogue essay for First Impressions: Contemporary Australian Photograms;

"The way that we view photographs has profoundly altered over the last decade as digital technologies have severed the connection between the image and the world ‘out there’. At the same time a number of Australian photographers are choosing to use various nineteenth century techniques, in particular the photogram, to produce pictorially sophisticated and resolutely contemporary images.

The photogram is one of the first photographic processes and technically the simplest.  In its rudimentary form a photogram is a camera-less image made by laying objects on sensitised paper and then exposing them to light. When first produced in the 1830s, the resulting images seemed to offer magical evidence of the material presence of objects. However, in the hands of today's artists, the process has often been conceptually transformed with the contemporary photogram less about the presence of objects as their absence. The shadowy traces of objects evoke the transitory nature of time and question the materiality of life."