The company has partnered with French manufacturer Pocheco for the project. Pocheco is supplying window envelopes “to Adare Post’s exact specifications” with a transparent window made of pulp instead of plastic film. The envelopes are described as 100% recyclable and biodegradable.

Adare Post uses around 115m envelopes a year, with the windows in the standard envelopes previously used resulting in around 30 tonnes of plastic landfill waste every year.

Adare SEC chief operating officer Tom Prestwich said the firm was “leading the way” with the switch: “Continually improved sustainability is one of our key business objectives, and an ideal that is shared by our clients,” he said.

“We are totally committed to finding new and innovative ways to further enhance our sustainability. It is essential if we are to achieve our objective of becoming one of the world’s most sustainable communications solutions companies.”

The firm aims to improve on its current standing by making it into the top 5% in the EcoVadis assessment of most sustainable communications solutions companies in 2020. At present it is in the top 15%.

The envelopes are imported from France in special wooden crates that are stackable and reusable. This cuts the number of journeys required from seven per month to three, which Adare SEC said reduced the carbon footprint involved by almost 60%.

Pocheco’s factory is in northern France near Lille, and the manufacturer is on a mission to achieve zero waste from its own operations. It produces 2bn envelopes a year, which it describes as ‘ecovelopes’ due to its products being recyclable and biodegradable.

Adare SEC has sales of £69.7m and employs 440 staff across four sites in Huddersfield, Redditch, Nottingham  and Guildford.It supplies secure and essential communications, and multi-channel delivery, for a broad range of clients including financial services firm Allianz, multinational bank Santander and conservation charity the RSPB.