THE UK’s largest envelope maker is continuing its growth after buying a Spanish rival.

Encore Envelopes, based in Washington, Wearside, makes more than a quarter of all envelopes delivered by Royal Mail.

The firm, and its sister company Encore Packaging Solutions, produce almost four billion of the 15 billion envelopes and packages delivered by postmen and women every year.

It also makes envelopes and packaging for businesses, including supermarket Tesco.

The company previously bought the UK division of Spanish competitor Tompla Envelopes, moving all work from Europe to Washington.

Bosses say the acquisition allowed them to secure the future of its 230-strong North-East workforce and invest in specialist machinery.

Russell Croisdale, Encore managing director, said: “Even in the digital age, packaging and envelopes are vital for the day-to-day running of every business in the UK.

“We have invested in the technology and equipment to ensure our products remain ahead of the curve with changing customer requirements.

“The strength of our business is built on the knowledge and expertise of our workforce and our expansion has enabled us to secure jobs in the North-East.

“Many of our team have been with Encore for more than 20 years, and we’re working hard and investing in our business to ensure we can celebrate with them again in a further 20 years.”