Self seal check envelopes from Checkomatic are double window envelopes for checks with a peel-and-seal closure strip. No licking, no moistening, no sponge required. You peel the adhesive strip, fold the flap down, and press. The seal holds. Two clear windows on the front display the return address from the upper left corner of the check and the payee address from the center, so you never need to address the envelope separately. Available in gummed or self-seal closure at Checkomatic. This listing is the self-seal version.
What Are Double Window Envelopes for Checks and How Do the Windows Work?
A double window envelope has two transparent windows cut into the front of the envelope. The upper left window frames the return address area of the check inside. The center window frames the payee name and mailing address. Both addresses are already printed on the check itself by your accounting software or by the pre-printed check stock. When the check is folded and inserted correctly, both addresses show through the windows without any additional printing, writing, or label application on the envelope.
This is what eliminates the envelope addressing step from the mailing process entirely. You print the check, fold it to the standard tri-fold position, insert it into the double window envelope, seal it, and it's ready to mail. The envelope already shows who it's from and who it's going to. No separate address label, no handwriting, no additional printer run for envelopes.
For businesses mailing checks to vendors, employees, or clients on a weekly or monthly basis, removing that one addressing step adds up to a meaningful time saving across a full payment cycle. For high-volume operations running hundreds of checks per month, the difference is significant.
Window Envelopes for Checks: Self Seal vs Gummed Flap
Checkomatic carries double window check envelopes in two closure styles. The self-seal version on this page uses a peel-and-strip adhesive that's covered by a protective liner until you're ready to seal. You peel the strip, fold the flap, and press. The bond is permanent. No moisture, no tongue, no sponge required.
The gummed flap version uses a traditional moisture-activated adhesive. You moisten the flap, fold it down, and it bonds when dry. Gummed envelopes are a common preference for businesses already set up with envelope moisteners on a mailing station, and they're typically slightly lower in cost per unit.
For the gummed version, browse the check envelopes category where both closure styles are available. If you're sealing envelopes by hand rather than with a machine, the self-seal version on this page removes the one step that most people find least pleasant about the process.
Which Business Checks Fit These Double Window Check Envelopes?
These self-seal double window envelopes are sized for standard 8.5" x 3.5" business checks. They fit the check-on-top voucher format, check-in-middle, check-on-bottom, and 3-on-a-page check formats from Checkomatic, as well as blank check stock in all positions. The envelope is designed for the standard business check fold: two horizontal folds that bring the check to letter size for the standard number 10 business envelope format.
To confirm the fit, fold a sample check from your current stock and insert it. Both windows should display the correct address fields without the text running behind the envelope edges or the fold lines.
These envelopes pair naturally with business checks on top, QuickBooks checks, and blank check stock. For matching deposit slips, browse business deposit slips.
Why Checkomatic for Self Seal Window Envelopes
Checkomatic has supplied business check accessories from Monroe, NY since 1997. Double window self-seal envelopes ship direct with no distributor markup, which keeps the per-envelope cost lower than what office supply chains charge for the same product. Orders ship in the standard 3 to 5 business day window with rush options available at checkout. Bulk pricing applies at higher quantities.
Customers who pair Checkomatic checks with Checkomatic envelopes consistently report that the window alignment matches perfectly on the first use. That matters because a poorly sized envelope that cuts off the payee address or obscures the return address defeats the entire purpose of the double window format.
Peel, fold, press, mail. Self-seal double window check envelopes from Checkomatic make outgoing check processing as fast as it can be without switching to a pressure seal format.
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