Premier 11B Size Security Envelopes – Pack of 100 | 80 GSM | Peel & Seal Make your everyday mailing secure and efficient with Premier Office Basics 11B Envelopes. Designed for consistent performance and trusted by professionals, these premium-quality envelopes are ideal for sending cheques, forms, invoices, or confidential correspondence. Measuring 90mm x 145mm, each envelope is crafted from durable 80 GSM paper and features a Peel & Seal closure for quick, moisture-free sealing. The interior is security printed to protect sensitive contents, while the printed Australia Post preferred postcode boxes ensure compliance and processing convenience. Whether for home, school, or office, this pack of 100 envelopes delivers reliability and peace of mind with every use.