 After gaining the Faculty of Design Certificate in Ceramics at the Royal College of Art, Clappison was appointed as Hornsea Pottery's Chief Designer in 1958.A studio was specially built on the Pottery site where he originated a whole range of designs for tablewares, novelties and gift wares.Clappison produced many designs for Hornsea Pottery such as his 'Home Decor' range, which are "highly reminiscent of the most advanced work in Studio Ceramics".