Optimal Size: Specially designed booklet mailing plain envelopes 6 x 9 ensure a snug fit for professional presentation. The size does not require extra postage and can be mailed as a letter. Compatible with laser and inkjet printers. Versatile Usage: Ideal for promotional materials, letters, catalogs, business materials, booklets, greeting cards, 5x7 photos, announcements, invitations, flyers, and more. Classic Gummed Sealing: Traditional gummed seal ensures secure and tamper-evident closure, keeping contents safe throughout mailing. Professional White: Crisp white color enhances professional appearance. Crafted from durable 28 lb heavy-duty paper, withstanding postal handling challenges. Compact 50-Pack: Perfect for occasional use or small projects, offering a beneficial option for exploring different envelope types. Weight: 0.86 pounds.