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In page Eric Hebborn:

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On 23 October 2014 the drawings went on to sell for over £50,000, with one sanguine drawing, after a design by Michelangelo, selling for £2,200, more than 18 times its expected price; Hebborn's modern drawing manual, The Language of Line, complete with pencil corrections and edits, sold for more than £3,000.[3] Although the identity of the successful purchaser of The Language of Line remains unknown, and no further copies are thought to have been in existence, Hebborn's former agent Brian Balfour-Oatts allowed The Guardian to have sight of the manuscript, which had been sent to him by a friend of the artist. Details of the previously unpublished text were published by the newspaper in August 2015.[4]