In the late eighteenth century, he worked under Mary Impey, the wife of Sir Elijah Impey, Chief Justice of Calcutta Supreme Court.^[2] Among the three artists she brought from Patna to make realistic sketches of birds and animals of her private menagerie, Zainuddin was the foremost. Zainuddin combined English botanical illustration with Mughal Patna Qalam style.^[2] In his paintings, modern critics appreciate the way a "bright, simple background offsets the keenly wrought details of plants and animals".^[3]

From 1777 to 1782, Zainuddin worked on Whiteman art paper manufactured in England for his transparent watercolor paintings. For his tinted drawings and sketches, he employed meticulous calligraphic strokes reminiscent of the works of Mughal Court artist Ustad Mansur. His drawings of mountain-rats, hanging bats, parrots, and storks are distinctive for having both aesthetic appeal and scientific value. These are now preserved in the Ashmolean Museum in Oxford.^[1]

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  Orange-headed thrush and an Acherontia moth on a Bauhinia
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  Chestnut-tailed starling on a Clerodendrum sp.
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  Harpactes erythrocephalus female on a melastome
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  Psilopogon zeylanicus on a Polyalthia
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  Anastomus oscitans with snail
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  Black-necked stork

Zainuddin's work was first exhibited in 2016 at the Royal Albert Memorial Museum in Exeter, as part of the Flower Power exhibition. At that point his name, written in an old hand-writing was taken to be "Jack Joyenadey." Since then, researchers working together with the museum staff, have deciphered his name.^[4] The updated exhibition is online. Subsequently, Zainuddin's work was exhibited in 2019 at London's Wallace Collection, along with that of 17 other artists commissioned by the British East India Company. The director of the Wallace Collection, Xavier Bray, told Smithsonian that in Zainuddin's paintings, "Everything is incredibly precise and beautifully observant."^[3]

• Study of a Stork

• Sheikh Zainuddin at Banglapedia