The Cumberland booklet mailer with window is designed for secure and professional mailing. Ideal for businesses and educational institutions, these envelopes ensure your documents remain confidential with a secretive pattern. The C5 size (162 x 229mm) and 90gsm weight make them perfect for various mailing needs, while the white colour adds a touch of elegance. These envelopes are laser printer compatible, featuring a heat-resistant glassine window to withstand the printing process. Responsibly sourced paper and FSC certification highlight the commitment to sustainability, making these envelopes a reliable choice for eco-conscious users