Without knowing who has created the works, people can bid for them on eBay until the auction, called The Big Art Secret, closes on Sunday. Proceeds from the sale will go to St Wilfrid's Hospice. Hockney's work is "an ink and colour crayon drawing on a postcard" and Emin has donated four postcards.
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Holly has Friday's forecast for the west of region.
Holly has Friday's forecast for the east of the region.
Holly has the latest forecast for the east of the region.