At Lob, we use pre-approved paper types and weights across our printer network. In ensuring uniform quality and consistency across all of our mail pieces, each paper source specification must fall within a small range. The specification/value range pairs are listed below:
Here’s a link to our template gallery to browse professionally designed templates for Letters, Postcards, Self- Mailers, Checks & Envelopes.
Letters and Envelopes Specifications
8.5" x 11" B&W and Color Letter Specs
- Basis Weight: 60# text
- GSM: 89 - 90
- Link to our design template for letters (6 pages or less)
- Link to our design center for letters (for over 6 pages but not exceeding 60 pages)
Standard #10 Outer Envelope Specs [Non-custom]
- Standard #10 Double-Windowed Envelope with Blue Inside Security Tint
- Envelope face size: 4.125" x 9.5"
- Window #1 size: 0.875" x 3.25"
- Window #2 size: 1" x 4"
- 24# White Wove
- Fits up to 6 sheets of tri-folded paper / 12 duplexed pages
- Link to our design template for standard letters (tri-folded)
Standard 9 x 12” Flat Envelope with Inside Security Tint [Non-custom]
- Standard 9 x 12” Flat Single-Window Envelope with Inside Security Tint
- Envelope face size: 9" x 12"
- Window #1 size: 4" x 3.375"
- 24# White Wove
- Fits between 7 to 60 sheets of paper / up to 120 duplexed pages
- Link to our design template for standard letters (full page)
*Automatically provided for orders over 6 pages; not customizable
Certified Mail Envelope
- #10 Certified Mail Windowed Envelope with Inside Security Tint
- Envelope face size: 4.125" x 9.5"
- Window #1 size: 3" x 8"
- 3/4" from left & right edge
- 9/16" from top & bottom edge
- 28# White Wove
- Fits up to6 sheets of tri-folded paper / 12 duplex pages
- Link to our design template for Certified mail envelope
Custom #10 Outer Envelope Specs
- Standard #10 Single-Window Envelope with Inside Security Tint
- Envelope face size: 4.125" x 9.5"
- Window #1 size: 1.125" x 4.5"
- 24# White Wove
- Fits up to 6 sheets of tri-folded paper / 12 duplexed pages
- Link to our design template for custom envelope
*Currently only supports letters; not available for checks or postcards
Standard #9 Return Envelope Specs
- Standard #9 Single-Window Return Envelope with Inside Security Tint
- Envelope face size: 3.875” x 8.875”
- Window #1 size: 1.125” x 4.5"
- Fits up to 6 sheets of paper / 12 duplexed pages (+ letter perforation required)
Business Return Envelope (BRM) Specs
- Standard #9 No-Window Return Envelope with Inside Security Tint
- Envelope face size: 3.875” x 8.875”
- Fits up to 6 sheets of paper / 12 duplexed pages (+ letter perforation required)
Note that all envelopes will expire in 6 months to ensure the integrity of the adhesives.
If you are an Enterprise customer interested in using custom envelopes, contact your Account Executive or Customer Success Manager.
Postcard Specifications
Postcards (Applies to 4” x 6”, 6” x 9”, and 6” x 11” )
- Basis Weight: 100# - 120# Cover
- GSM: 255 - 325
- Full Bleed 1 Side UV Gloss
*If you require a different postcard size, reach out to Lob support to submit a feature request.
Self-Mailer Specification
Bifold Self-mailers
- Basis Weight: 80# Cover with Gloss
- GSM: 218
- Full Bleed
- 1 Side UV Gloss
- Adhesive: Stain resistant, low tack, clear fugitive glue
*While we typically have a FSC-Certified and 10% PCW Product requirement for our sourced paper across our network, Lob will make exceptions to relax our paper requirements during the supply chain and paper supply shortages.
If you are an Enterprise customer interested in using folded self-mailers, contact our Sales team or your Customer Success Manager.
Checks
- Measures 8.5" x 3.625" in size.
- Link to our design template page for checks.
- Sent in #10 white 2-window envelope
- Printed on bank-grade chemical reactive paper (with watermarks, warning bands).
- Paper is perforated with the bottom ⅔ available for the sender to include a message
- Include a three-dimensional graphic foil that is embedded into the check, along with fugitive ink, to provide additional protection against duplication of the document.
- Include a prismatic multicolored background with subtle graduations is added to make copying and reproducing difficult.
- During every stage of production, we produce these checks with controlled stock which ensures the security of the mail piece. The Padlock Icon printed on the checks ensures that the product meets or exceeds industry guidelines.