On examining a drawing by Georg Philipp Rugendas (1701–1744) Hunter with Dogs Chasing a Deer, a watermark was noted by placing the drawing over a light source. The paper's thickness made tracing the watermark difficult, so capture using a Carbon-14 source was undertaken.
A Carbon-14 transparent polymer plate emitting radiation was placed under the area where the watermark can be found and then a sheet of photographic film was placed face-down on top of the paper, directly over the Carbon-14 plate. The radiation emitted from the Carbon-14 plate passed through the watermark, and an image was recorded on the photographic film which became visible when the film was developed.
The process takes place in a darkroom environment and exposure times vary from four to eight hours.