These envelopes are made from 350gsm white all board material and feature a wallet-style design with an side opening from the long end. They are equipped with a peel and seal closure for easy and secure sealing, as well as a tear strip for effortless opening. The sturdy construction and professional appearance make them suitable for a variety of mailing needs, providing a reliable and presentable solution for sending documents, cards, and other flat items. Whether for personal or business use, these envelopes offer a practical and professional option for securely enclosing important materials.