Chemigrams are not photography, really. But something very close, of course. They are made with chemicals, in this case the developer and fixing of black and white gelatine process, and a short exposition to the sun. Every artis has his own way to obtain this abstract, and strangely colorful, kind of images. But the results can be very appealing, I think. The original chemigram is duplicated and digitally manipulated to extract the best.
black and white paper, chemicals