The new card, which biodegrades within months as opposed to hundreds of years for the conventionally produced alternatives, will be offered as an environmentally friendly alternative to customers.

More than 9,000 of the cards have already been sent to customers and Stena Line marketing manager Heather Gawley described them as offering a "biodegradeable alternative without compromising quality, durability and value at a time when we were looking closely at improving environmental performance across the company."

PCS managing director Rob Nicholls said: "We are delighted that Stena Line has made the move. It's part of our commitment to converting 50% of our business to the green card in the next five years. Their example - as a world-leading player in their field - will give us a great platform to convert others."

The £5m turnover company launched the green card service at the beginning of the year, producing 2m cards for Coop DanmarkPlus on its KBA Genius 52 UV press using bioPVC materials.

PCS produces more than 50m cards a year for household names across the UK including Next, Virgin, Ikea, Ford, Iceland and npower.