#10 Window Business Envelopes, White, Gummed Seal
The #10 window envelope is the standard business mailing envelope in the United States. The clear poly-film window on the left face displays the recipient's address from the tri-folded document inside, eliminating labels, envelope addressing, and the separate step of printing or writing on the envelope face. Fold your letter, invoice, or statement into thirds with the address block positioned behind the window, slide it in, and the piece is ready to seal and mail. At Business Envelopes, this envelope ships blank for everyday correspondence or with your logo and return address custom printed. Free shipping on every order with no minimums.
#10 Window Envelope Dimensions and Window Measurements
Buyers searching for #10 window envelope dimensions typically need these numbers to verify software alignment or confirm postal compliance before placing a volume order. Here are the full specifications:
- Envelope size: 4 1/8 x 9 1/2 inches (standard #10 commercial format)
- Window size: 1 1/8 x 4 1/2 inches, clear poly-film panel
- Window position: 7/8 inch from left edge, 1/2 inch from bottom edge
- Paper stock: 24 lb white wove, smooth finish, 92 brightness
- Seam construction: Dual diagonal seams, V-shaped flap
- Closure: Moistenable gum flap
- Printer compatibility: Laser-safe and inkjet-safe
- USPS compliance: Window placement meets postal automation requirements
The window position at 7/8 inch from the left edge and 1/2 inch from the bottom is the industry-standard measurement that aligns with address blocks in QuickBooks, Xero, FreshBooks, Microsoft Word mail merge, and virtually every standard business document template without any margin adjustment. When your document is set up to standard letter-format specs, the address falls inside the window on every piece without checking or adjusting.
Business Envelopes With Window: What the Format Does Operationally
The window isn't decorative. It eliminates a step from every single outgoing piece in a mailing batch. For a billing department processing 300 invoices a month, that's 300 times no one has to address an envelope, apply a label, or run envelopes through a separate printer. For a law office sending weekly client correspondence on letterhead with a standard address block, the window handles addressing automatically for every piece. The operational value compounds at volume in ways that are easy to underestimate until you're no longer doing the manual addressing step.
The 24 lb white wove stock is calibrated for this format. It's substantial enough to feel professional in the hand and opaque enough that the document contents don't show through the paper body. The gum flap activates with a damp sponge or moistening tool and bonds firmly across the full width of the flap. The dual diagonal seams hold the envelope structure through postal sorting equipment without the corners pulling or the body deforming under handling pressure.
Custom Printing on #10 Window Envelopes
Return address, company logo, tagline, and mailing indicia printed directly on the envelope stock before shipment. The printing sits to the upper left of the face, clear of the window zone, so the address display is unobstructed and the brand treatment is visible the moment the piece is picked up. PDF proof before production. Artwork on file for reorders. Blank stock ships same or next business day. Custom printed orders ship in 7 to 10 business days from proof approval.
For the same envelope format with a security tinted interior that blocks document contents from showing through the paper, see the #10 window tinted gum flap. For a peel-and-seal closure that requires no moisture activation, the #10 window tinted self-seal handles high-volume runs cleanly. For billing programs that need both the return address and the recipient address showing from the document inside, see the double window envelope range. Browse the complete window envelope catalog for every size and closure type we carry.
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