HERKKA #10 Security Self-Seal Envelopes, No.10 Windowless White 500-Pack — 24 lb, Printer-Friendly

HERKKA #10 Security Self-Seal Envelopes are windowless, navy-tinted business envelopes with a peel-and-seal closure built to protect confidential mail and work with standard printers.

These envelopes are made for everyday business and home-office mailing: a 500-count pack of size 4-1/8 x 9-1/2 inch, 24-lb white stock with a heavy interior security tint and a strong self-seal strip. The blank, windowless front lets you print addresses or apply labels while the dark inner pattern hides contents from view. They combine simple, adhesive closure with a design that fits checks, invoices, statements and other letter-sized documents.

How do these envelopes protect private information?

The interior of each envelope is printed with a dense navy security pattern that obscures text and prevents viewing through the paper. This reduces the chance of accidental exposure when mailing financial or sensitive paperwork.

• Dark, high-coverage security tint inside each envelope
• Windowless exterior keeps contents concealed
• 24 lb stock adds opacity and durability

Will these work with my printer and standard mailing tasks?

Yes — the blank front is optimized for inkjet and laser printers, and the no-window design simplifies addressing, bulk labels, or computerized check printing. The size matches standard business envelopes for routine mailings.

• Fits standard #10 envelope feeders and templates
• Compatible with most inkjet and laser printers
• Blank face allows for full-bleed addresses or mailing labels

How secure and easy is the closure?

The peel-and-seal adhesive delivers a fast, reliable closure without moisture or licking. The full-width adhesive strip forms a tight seal that resists accidental opening during handling and transit.

• Peel-and-seal strip for quick, mess-free sealing
• Strong adhesive prevents splitting under normal mailing stress
• Consistent closure across large mail runs

How does the pack size help my office or household?

A 500-count supply reduces frequent reorder needs and suits high-volume mailing, bookkeeping, or seasonal billing cycles. Keeping a bulk supply on hand saves time and ensures you can send outgoing mail without delay.

• 500 envelopes per carton for long-lasting use
• Economical for small businesses, schools, and busy home offices
• Ready for mailings, invoices, checks, and statements

Who is this for? These HERKKA #10 Security Self-Seal Envelopes are designed for small businesses, accounting departments, legal practices, property managers, and anyone who needs a reliable, private way to send documents. If you print addresses, handle recurring invoices, or need a discreet envelope for checks and statements, this 500-pack supply provides a practical, printer-friendly solution.