Pack of 250 Brown Envelopes 353x250mm. This pack of 250 Brown Envelopes, sized at 353 x 250 mm, is perfect for mailing large documents, promotional materials, brochures, and artwork. Made from durable brown Kraft paper, these envelopes offer a strong, eco-friendly solution for your mailing needs. Their secure and spacious design ensures your contents are well-protected, while the rustic appearance adds a professional, yet natural touch to any mailing.