The streets of Sofia and other Bulgarian cities and towns are lined with stalls selling martenitsi, the traditional talismans exchanged on March 1 every year - and again, sales people have tapped into popular culture, with some martenitsi featuring Hannah Montana and Barbie.

In recent years, manufacturers of martenitsi have come up with new variations of the ancient tradition, drawing on such popular figures as Harry Potter.

The advent of pop culture figures is not the only phenomenon that has re-shaped Bulgaria's martenitsa market. In the past few years, local small-scale manufacturers have complained of being undercut by martenitsi made in China for the Bulgarian market.

Baba Marta is a mythical character in Bulgarian folkore, whose name is associated with the month of March.

March 1 is celebrated as the day of the arrival of Baba Marta and is the name day of everyone called Martha, Martin or Martina.

Martenitsi, traditionally made from twisted red and white thread, are considered to symbolise a wish for good health, and are seen as the heralds of the coming spring and life in general.

The white colour of the martenitsa initially symbolised the male, strength and the light solar zone.

Later influenced by Christian mythology, it became a symbol of virginity and virtue – white being the colour symbolising Jesus.

The red colour in the martenitsa represents the female and health, a sign of blood, conception and birth.

Many years ago, women’s wedding dresses and traditional costumes used to be red.