LONDON (AFP) - Official royal wedding china to mark the marriage of Britains Prince William and Kate Middleton next April went on sale Monday, its producer said. The three pieces a tankard, plate and pill box were handcrafted using methods that date back 250 years and have been personally approved by the prince and his fiancee. They were created by designers from the Royal Collection, the art collection of the royal family which also has a retail arm, and made in traditional potteries in the central city of Stoke-on-Trent. They are made from English fine bone china and have been decorated with the couples entwined initials, with the princes coronet appearing above the letters.The Royal Collection said its staff had been working flat out since the couple announced their engagement on November 16 after an eight-year romance. Their wedding will take place on April 29 next year at Westminster Abbey in London. Each English fine bone china piece bears the couples entwined initials in gold and silver surmounted by Prince Williams coronet and the wedding date, said Nuala McGourty, the Royal Collections director of retail. Doves, white ribbons, and hearts in silver, gold and grey, set against a pale-grey striped background, decorate the whole range.The tankard costs 35 pounds (40 euros, 54 dollars), the plate 40 pounds (47 euros, 62 dollars) and the pill box 25 pounds (30 euros, 40 dollars).