The ‘Windows of the World’ collection, which is available with immediate effect, becomes part of the firm’s Premium Office range.

Blake said the collection, which features window positions to suit a wide number of European countries, has been designed to support the firm's expanding European customer base by making direct mail campaigns from the UK to a selection of European countries easier and less confusing.

Blake marketing manager Alison Wilde said the window positions of envelopes across Europe vary widely: “We’ve developed this range in response to our own research and feedback from customers in the UK and across Europe.

“For example, Sweden prefers a right hand window compared to Germany, Poland and Austria, who favour the left.”

Countries catered for include: Austria, Czech Republic, Denmark, Finland, France, Germany, Hungary, Luxembourg, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain and Sweden. Also included are envelopes for Swiss-French and Swiss-German markets.

The 120gsm envelopes in the range are available in a number of different sizes for each country, have a five-year shelf life and are compatible with digital, laser and inkjet technologies.

Blake recently launched more than 300 new products, all of which are detailed in the firm's new product catalogue, i16.

It also secured a new distribution partnership with office supplies distributor Spicers in October and won a major retail contract with office supplies firm Staples in April.

The company, which has 54 staff and is anticipating a turnover of £25m this year, has around 7,000sqm warehouse space and 1,580sqm office space.

The business designs and sells more than two billion envelopes a year. It currently ships to 18 countries, including Australia, Barbados, Jamaica and several European states.