Sarah Cove ACR founded the Constable Research Project in conjunction with the V&A Museum in 1986 to study John Constable RA’s materials and techniques from the technical and scientific point of view. Since then she has examined over 250 works from collections worldwide, from tiny oil sketches on fragments of canvas, paper supports and boards to the ‘six-footers’, some of Constable’s most famous and iconic paintings including The Haywain (1821), The Leaping Horse (1825) and Salisbury Cathedral from the Meadows (1831). She has developed a technical chronology that assists with the dating of his known works, relatively few of which were signed and dated by the artist, and is also useful for the attribution (or not) of newly discovered pictures. Sarah Cove has been instrumental in the attribution of three significant Constable oils for BBC1’s Fake or Fortune? series, appearing in 2014 and 2017. In 2014 she set up a Facebook page that is hugely successful in raising awareness of her research so that now she is regularly contacted by people that think they have a found a previously unknown Constable!! Some have, some have not, as you will see in this lecture which gives a ‘behind the scenes’ look at how such decisions are made and will describe some extraordinary successes but also crashing disappointments. Stories will include, at opposite extremes, a hugely publicised oil sketch reputedly worth £250,000 that turned out to be a copy and the chance discovery of a fabulous, almost abstract, oil study of the 1830s that had formerly belonged to an American G.I.