Duchess of Cambridge: First official painting revealed

The first official painting of the Duchess of Cambridge has been unveiled.

It was painted by the artist Paul Emsley and took several months using a technique of building thin layers of oil and glazes on canvas.

The duchess sat for the artist twice. Mr Emsley also worked from a series of photographs he took of Catherine.

The portrait is on show at London's National Portrait Gallery, of which the duchess is patron.

Nicholas Witchell reports.