Chemigrams were invented by Pierre Cordier in 1956. The chemigram combines the physics of painting and the chemistry of photography; without an enlarger and in full light. The light-sensitive photographic paper is manipulated by adding a resistant, simple household materials like oil, honey or vinegar, and exposed to the light while developing the paper. Thus the developing process is altered, giving color to the black and white paper. The color differs from brand to brand.