9" x 12" booklet envelopes are made with durable stock for home or office mailing, organizing and storing. Whatever your needs, booklet envelopes are a must for keeping projects, files and mailings manageable. Envelopes open on the long side for easier inserting and removing. They are made from sturdy, 24 lb. white wove stock to withstand extensive handling and mailing. Contents are protected during use to give you assurance that they arrive unharmed. They are perfect for folded or smaller documents. Fully gummed flaps ensure a secure, permanent seal.