#10 Envelopes
#10 Envelopes (Standard 4 1/8" x 9 1/2")
The #10 Envelope is the universal standard for US business mail. Sized exactly at 4 1/8" x 9 1/2", these envelopes are engineered to fit 8.5" x 11" documents folded in thirds. Browse our selection of 10 envelopes below, featuring various window placements, security tints, and sealing options for every office need.
1. Security vs. Regular
Choose Security 10 Envelopes with interior blue/black tint to hide confidential data (checks/SSNs). Choose Regular (White Wove) for standard letters and marketing.
- Most Popular: Security Tinted #10 Window
- Standard: Regular White #10 (No Tint)
2. Peel & Seal vs. Gum
Peel & Seal 10 Envelopes feature a self-adhesive strip for manual mailing (no moisture). Gum Seal is the standard lick-and-stick option for machine insertion.
- Time Saver: Self-Seal #10 Window
- Machine Ready: Standard Gum #10
3. Window vs. Double Window
Standard Window: Best for invoices/letters with one address. Double Window 10 Envelopes are specifically aligned for checks (QuickBooks compatible).
- Standard: Left Window #10
- For Checks: Double Window #10
Standard #10 Envelope Specs for Automation
Buying 10 envelopes for automatic insertion? Our standard gummed envelopes are engineered to meet USPS "Machinable Letter" standards, preventing jams in Pitney Bowes and Neopost inserters.
- Throat Depth: Standard commercial flap depth for high-speed insertion.
- Paper Weight: 24lb White Wove (Laser Safe) is the industry standard for 10 envelopes.
- USPS Dimensions: 4.125" x 9.5" aspect ratio qualifies for automation postage rates.
#10 Envelope Technical Specifications
| Dimensions | 4 1/8" Height x 9 1/2" Width |
|---|---|
| Document Size | Fits 8.5" x 11" Paper (Folded in Thirds) |
| Flap Style | Commercial Flap (V-Shape or Straight) |
| Max Thickness | Standard 1/4 inch (approx 5 sheets) |
The Anatomy of a #10 Envelope
While they all share the same 4-1/8" x 9-1/2" dimensions, the construction of the envelope determines its best use. Understanding these technical details ensures you order the right product for your specific equipment and needs.
1. Commercial vs. Square Flap
The Commercial Flap is the standard V-shaped flap. It is designed for high-speed automatic inserting machines used by large mail houses. The Square Flap offers a more contemporary, elegant look, often used for invitations or premium direct mail.
2. Diagonal vs. Side Seams
Most #10 envelopes feature Diagonal Seams (the paper overlaps in a V-shape on the back). However, for heavy graphics or full-bleed printing, we recommend Side Seam construction, which provides a larger uninterrupted printable area on the back.
3. Standard Window Positions
Our #10 Window Envelopes use the industry-standard position (typically 7/8" from the left and 1/2" from the bottom). This ensures compatibility with most accounting software layouts and meets regulations for USPS Machinable Letter standards.