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#10 Single Window Security Envelopes, Self Seal, 500 Count

7 reviews

  • Durable and professional go-to standard business envelope for mailing invoices, statements, and other office mailing needs
  • Roomy enough for a return envelope to be included, so you can get paid faster
  • Low profile flap design creates a wide opening for easy and quick envelope stuffing 
  • Peel and seal closure is quick and easy to use without any need to lick or moisten the glue 
  • Dark security tint lining keeps your important documents securely concealed throughout transit


It’s no secret that the #10 security envelope is the workhorse of business mailings, and we’ve designed our peel and seal #10 envelope to keep your documents safe and secure behind a strong glue seal throughout transit.

Our most popular business envelope is made from a durable 24lb white wove paper and comes equipped with a low profile flap design, which makes it easy to fold and stuff up to 10 sheets of standard letter size paper inside with room for a #8 or #9 return envelope as well – so you can make it simpler than ever for your clients to quickly return payments to you. And with our dark security tint lining the inside, your confidential mail will stay concealed and secure all the way to its destination. It’s an envelope choice that’s simple enough for everyday letters and statements, yet professional and secure enough for even high-profile business communications.


#10 Single Window Envelopes

Part #: BSS-92588-004

We stand behind our products completely. We understand that buying products online can sometimes be difficult because you cannot physically see what you are buying; however, if our product is not exactly what you are looking for or does not meet your expectations, then we welcome you to send them back anytime for a 100% refund. Click here for more information regarding refunds or returns >

Key Features:

  • #10 single window envelope
  • Dimensions: 9 1/2 inches X 4 1/8 inches
  • Security lining
  • 24lb white wove paper
  • Package quantity: 500 Count


  • This envelope is equipped with a self seal, which means it requires that you peel away the protective strip to reveal the glue. It does not require moistening, but cannot be used in a bulk mail machine. For envelopes that can be used in a mail machine, you’ll want to use a gummed seal envelope.
  • This envelope is not suitable for printing in a laser printer, as the heat will melt or warp the window.
  • While this envelope will work with QuickBooks invoices, it is NOT suitable for sending QuickBooks checks, as check information will not line up properly in the windows. Please click here for envelopes suited for mailing QuickBooks checks.
  • Not sure what type of number 10 envelope is right for you? Read our blog post about #10 envelopes, wherein we help you wrap your head around every detail you never knew you needed.

Product Details:

  • Brand: Blue Summit Supplies
  • Part #: BSS-92588-004
  • SKU: 06-5BHM-5L9Q
  • Barcode: X0019S0P0X
  • Package dimensions: 12 x 10.2 x 3.5 inches
  • Package weight: 6.35 pounds
Customer Reviews
5.0 Based on 7 Reviews
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Filter Reviews:
    KIRK T.
    United States
    Office mngr

    works well Thank You

    Jordan S.
    United States United States
    Extremely Satisfied

    I love that I no longer have to lick the envelopes!!

    Kelli L.
    United States United States

    Fast delivery and quality product! Thanks, we will definitely re-order!

    Gregory D.
    United States United States
    Excellent quality Product

    These envelopes are made of top quality opaque paper with security tint my customer love coupled with a secure peel-n-stick sealing envelope to avoid that nasty lick-n-stick taste.

    Kyle W.
    United States United States
    Great envelopes, Great Price!

    The self seal is the biggest reason I like this envelope. But I also really like the auto renew option so I don't have to try to remember to order more. Plus the 10% off makes it even better!