Photo-grass photographs British artists win the L'Oréal Art and Science of Color Prize

On 25 January, at the Musée Malliol in Paris, the British artists Heather Ackroyd and Dan Harvey were presented with the Art and Science of Color Prize, awarded by the L'Oréal Art and Science Foundation. The prize was established in 1997 by the Tokyo-based foundation, the brainchild of Tetsuzo Kawamoto, for Japanese artists and scientists. It is intended to promote a creative dialogue between art, science and colour. This is its first international year, involving a multinational jury, including myself. The winners, Ackroyd and Harvey, use grass as a novel surface for producing photographic images.

Ackroyd and Harvey's Mother and child, created by grass photosynthesis.

Anyone who has seen the effect made by something lying on a grass lawn for a few days will have noticed the yellowish imprint when it is lifted away. The pale silhouette may be considered as a kind of photographic negative, fading from view when sunlight restores the yellowed grass to its former greenness. Using the photosensitive property of grass, Ackroyd and Harvey have collaborated with scientists at the Institute of Grassland and Environmental Research (IGER), at Aberystwyth in Wales, to perfect the production of fully legible, ‘living’ photographs on a germinating lawn.

Their positive photographic images are formed by the projection of a black-and-white negative onto the surface of the growing grass. Such is the sensitivity of each germinating blade of grass that it produces a chlorophyll concentration that corresponds directly to the quantity of light available to it. Leaves of varied colour, from a rich, dark green to a sickly pale yellow, combine to form tonal images of a subtly elusive kind. They strongly recall the soft beauty of the callotypes made by William Henry Fox-Talbot during the years immediately following the first announcement to the public of the rival French and British photographic processes in 1839.

The biological researchers with whom Ackroyd and Harvey worked at IGER during 1997–98, as a result of a Wellcome ‘Sciart’ award, are developing techniques for controlling the enzyme that degrades chlorophyll as a leaf dies. They have devised ways of modulating the expression of the gene responsible for the enzyme that causes the senescence of the green leaves. The scientists' newly engineered ‘staygreens’, which resist yellowing senescence, possess obvious potential for increasing the longevity of the artists' evanescent photographs. On their own behalf, Ackroyd and Harvey have placed particular demands on their unconventional medium in order to achieve minute gradations in green tonality. Their interests have been served by IGER's use of advanced visual analysis techniques, in particular the high-resolution imaging technique of hyperspectral analysis.

Ackroyd and Harvey's beguiling results, which revive the strange visual magic of early photographic images from more than 150 years ago, are underpinned by today's most advanced plant genetics and optical precision. Their grass-works testify to the ceaseless wonder of living nature in all its responsive subtlety, and to the more creative potential of human intervention in nature's supersensitive systems. Not least, it is a relief to find genetic engineering featuring in a story that does not involve scares — whether well- or ill-founded.