FOUR stamps celebrating St Patrick's Day, designed by Colchester design consultancy Silk Pearce, go on sale today . Commissioned by Royal Mail, the stamps are part of a series to promote the four countries of the United Kingdom and highlight some of Northern Ireland's top tourist destinations.

FOUR stamps celebrating St Patrick's Day, designed by Colchester design consultancy Silk Pearce, go on sale today .

Commissioned by Royal Mail, the stamps are part of a series to promote the four countries of the United Kingdom and highlight some of Northern Ireland's top tourist destinations.

The “Celebrating Northern Ireland” mini sheet of stamps features Carrickfergus Castle on the banks of Belfast Lough, the Giant's Causeway, one of the UK's greatest natural wonders, a photograph of Belfast's Queen Bridge and a newly-commissioned illustration of St Patrick by Claire Melinsky. The background to the sheet is the Cushendun Hills.

“St Patrick's Day is not an event that the design team at Silk Pearce would normally celebrate but clearly this year we will be raising a glass or two of Guinness… after hours, of course!” said Peter Silk, joint creative director at Silk Pearce.

“We are always flattered when Royal Mail invites us to design commemorative stamps and it is a great feeling knowing that our work will be seen, admired and treasured across the world as people get ready to celebrate all things Irish.”

The stamps have been released a few days ahead of St Patrick's Day, which this year has been brought forward by two days to March 15h to avoid it falling in Holy Week, so people can buy them to use on any cards they may send to mark the patron saint's day.

The first two sets in the “Four Countries” series, which marked the national identities of Scotland and England, were issued in 2006 and 2007. The final set for Wales is due out on St David's Day on March 1, 2009.