#11 Envelopes - 4 1/2 x 10 3/8

This size covers regular, window, open-end, clear cello, and Tyvek construction. #11 paper options span 14 lb to 32 lb across standard, window, and specialty business styles. A clear 1.6 mil cello option is included for business mail that benefits from visible contents. The #11 assortment combines standard business styles with window, cello, and Tyvek choices for recurring office and administrative mail.

Window placements keep selected address or form information visible, supporting efficient business mailing. Tyvek gives #11 business mail a lightweight, tear-resistant choice for documents that may face more handling in transit. Clear cello keeps contents visible when presentation or quick identification matters. Window, Tyvek, and clear cello options provide different levels of visibility and durability for recurring business workflows.

#11 envelopes work well for longer business letters and multi-page correspondence, while also handling invoices, statements, payments, notices, checks, and forms. Long business envelopes support accounting teams, schools, nonprofits, healthcare offices, administrative departments, and businesses that send recurring mail. Using the same #11 construction across recurring workflows can help offices keep window placement, durability, and presentation consistent.