Candlemaker David Constable on his work by royal appointment
11 July 2013 Last updated at 13:55 BST
More than 60,000 visitors are expected at the Coronation Festival in the grounds of Buckingham Palace this weekend.
Two hundred companies who have been awarded the Royal Warrant of Appointment will be at the festival - but only three of them are Welsh.
David Constable, who has been making candles for the royals for over 30 years, will be at the event.
From his tiny workshop in Blackwood, Caerphilly county, he makes thousands for the Royal household every year.
Mr Constable gave BBC Wales' Matt Murray a demonstration of how the candles are made.