9 X 12 Booklet Envelopes - 28lb. Brown Kraft (50 Qty.) Hightest Quality Kraft Envelopes A Quantity of 50- 9x12 Booklet Envelopes - 28lb. Brown Kraft Regular Gummed Flap Brown Kraft booklet envelopes. Great for mailing Invoices, statements, catalogs or announcements brochures, annual reports, and product literature.