Weeks before Prince William and Kate Middleton are to wed, a New Zealand commemorative stamp has marked their union in a rather awkward way — by approving their split.

The separation would be via a perforated line dividing a photo of the couple. The stamp tears apart so each half of the engagement portrait can serve as its own individual stamp.

The ominous New Zealand Post design has been branded "bizarre" and "embarrassing" by Hugh Jefferies, the editor of Gibbons Stamp Monthly, noting it's also strange that each side of the stamp bears a different price.

While they are valued at 5.80 NZD ($4.25 Cdn.) printed together, William's side of the stamp is worth 3.40 NZD ($2.49) and Middleton's lone stamp comes out to a more modest 2.40 NZD ($1.76).

Royal stamp mishaps nothing new

Royal stamps suggesting a soon-to-be-wed couple's separation are not new, according to Jefferies.

In the lead-up to the 1981 wedding between Prince Charles and Lady Diana, Jefferies said, Australia's postal service released a royal stamp showing Charles and Diana turned away from one another. The design caused much criticism.

"Whoever designed this will have egg on their face and someone's head will roll," Jefferies told Britain's Telegraph newspaper.

At the very least, he said, collectors will be delighted to add the unusual item to their books.

It wouldn't be New Zealand Post's first printing faux-pas involving the 2011 Royal Wedding stamp pack. The state-owned postal service recently featured the wrong birth date for Prince William on cover sheets for collectors'-edition stamp sheets. The presentation text said William was born May 21, 1982, when his birthday was in fact June 21. The packs were later recalled.

Buckingham Palace must approve of stamp designs featuring the royal couple, Jefferies said. In the case of the split stamp, Jefferies said he wouldn't be surprised if Buckingham Palace had been shown the design without the controversial perforated line.