Custom #10 Envelopes
The Standard for Business Correspondence.
The #10 Envelope (measuring 4-1/8" x 9-1/2") is the absolute standard for business mailing in the United States. Designed specifically to hold a standard 8.5" x 11" sheet of letterhead folded in thirds (tri-fold), these envelopes are the engine of modern commerce—perfect for invoices, monthly statements, legal letters, and direct mail marketing.
At Granite Woods Printing, we offer the widest selection of custom 10 envelopes, including Commercial Flap for automatic insertion machines and Peel & Seal for manual office use. Not sure which design works for your brand? Visit the our blog for design tips, logo placement guides, and marketing inspiration.
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.