A watercolour of Vanilla (Vanilla planifolia), with the life cycle of the Gulf Fritillary Butterfly (Agraulis vanillae) and of an unidentified insect. This is a version of plate 25 in Merian's Metamorphosis Insectorum Surinamensium. In the text accompanying the plate, Merian described the beauty of the Gulf Fritillary, and noted the silver spots on its wings, which she has reproduced with silver paint.

Maria Sibylla Merian was the daughter of the printmaker Matthias Merian, and the step-daughter of the still-life painter Jacob Marrel. She was a talented artist, who was trained in flower painting by Marrel. From an early age, she was fascinated by insects and their life cycles, and undertook research into the phenomenon of metamorphosis, which was then only partially understood. She published her findings in a series of books, illustrated with beautifully-composed plates in which each insect life-cycle was illustrated on the appropriate food plant. In 1699, having encountered exotic insects in the cabinets of natural history collectors in Amsterdam, Merian and her younger daughter Dorothea set sail for Suriname, in South America, which was then a Dutch colony. There, they studied the life cycles of Surinamese insects until their return to Europe in 1701. Merian published her Surinamese research as the Metamorphosis Insectorum Surinamensium (The Metamorphosis of the Insects of Suriname) in 1705. The book was very well-received, and by her death Merian was well-regarded throughout Europe as both an entomologist and an artist.

This is one of a set of luxury versions of the plates from Merian's Metamorphosis Insectorum Surinamensium, published in Amsterdam in 1705. To make these versions, Merian (probably assisted by her daughters) appears to have inked sections of each etched plate and run it through the press to create a partial print. While the ink of that print was still wet, she placed a sheet of vellum against it, transferring a reverse image onto the vellum. This ‘counterproof’ was then worked up and coloured by hand. The Royal Collection plates are partially printed and partially hand-drawn, the printing mainly being used for the insects. As Merian was only transferring selected areas of the printed image, she could vary the arrangements of the plates, with the positions of the butterflies and moths subtly altered to create unique compositions.