 Donkin died in 1855 and was buried in a family plot in Nunhead Cemetery, south London.In 1820 Donkin worked with Sir William Congreve on preventing the forgery of excise stamps, using a method of two-colour printing with compound printing plates.Working with his partner John Wilks, he produced a machine which was used for the Excise and Stamp Office and also for the East India Company at Calcutta.