The Blackburn-based company is now certified to the environmental standard for the direct mail industry, as well as having ISO 14001, FSC and PEFC accreditations.

Daniel Bolton, estimator at the £20m-turnover Heritage Envelopes, said: "We got the PAS 2020 standard on the back of becoming ISO 14001 certified.

"Our environmental credentials now surpass the requirements of both PAS 2020 and the Royal Mail Sustainable Mail scheme."

He added that the company, which has 150 staff, aims to be as efficient as possible for its customers, and that they have benefited from the business having PAS 2020.

PAS 2020 aims to promote direct mail as a self-regulating industry and provides businesses with a standard against which the environmental performance of a direct marketing campaign can be independently certified.

It was launched on 21 January last year and is commissioned by the Direct Marketing Association.