Royal Mail's First Class Stamp Prince Charles, Queen Elizabeth, Prince George Duke of Edinburgh

ROYAL CLASS: Ahead of Queen Elizabeth’s 90th birthday Thursday, the Royal Mail on Wednesday released a specially commissioned stamp featuring the monarch, Prince Charles, the Duke of Cambridge and Prince George.

The first-class stamp features four generations of the royals posed together in the White Drawing Room, photographed by Ranald Mackechnie.

Prince George is pictured holding hands with his father while standing on a stack of blue foam blocks wearing a Rachel Riley white button-down shirt and blue shorts. The royal toddler previously wore the outfit in the first official portraits with Princess Charlotte released by Kensington Palace.

RELATED STORY: Portrait of Prince George With Princess Charlotte >>

Six more stamps will be issued focusing on the Queen to mark her birthday with images from her family and royal life.

The price for a book of first-class stamps is 3.84 pounds, or $5.52, and it is sold at Royal Mail and on the post office’s Web site.