Blue Summit Booklet Envelopes with Window for Bulk Business Mailing, 9” x 12” Envelope with Outside Seam and Gummed Seal, 28lb White Wove Paper, 500 EnvelopesBooklet envelopes are designed to fit standard letter size paper (8. 5 x 11) with a 12 opening to quickly stuff up to 60 sheets of paper. Single window design shows address or other important business information to the recipient, making them more likely to open. Gummed flap closes securely with moisture, no glue or tape required, and keeps documents safe during transport while being more cost effective than self seal options. Booklet envelopes are