This booklet envelope is great for mailing out sales brochures, annual reports, product literature and other materials. Opens on the long side for easy paper insertion. A cost-effective envelope that gets the job done. Heavily gummed for a secure seal. Envelope Size: 10 x 13; Envelope/Mailer Type: Booklet/Documents; Closure: Gummed Flap; Trade Size: NA. Quality Park First Class Envelope