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Security tint; forget thin, numbers and other data within, easily read envelopes these premium #9 Security Envelopes are designed with security tinted wave patterns which easily obscure details, perfect for mailing business statements and invoices while protecting sensitive information.9
Double windows; professional, each envelope contains two front windows, eliminating constantly printing and hand writing addresses, easily read double front windows suitable for standard business and legal mailings, advertising campaigns and many more, a 1-3/16" X 3-1/2" top window positioned 3/8" from the left and 2" from the bottom and the bottom 1" X 4" window is 3/8" from the left and 1/2" from the bottom.

Save time with easy to use flip and seal self-seal design; With no need for licking or moistening, our self seal design allows for sending hundreds of invoices quickly and easily and is guaranteed to stay sealed with no need for tape or glue sticks.

Perfectly fits QuickBooks Invoices and business billing statements. 500 pack self seal envelopes:herkka #9 security envelopes are designed with peel & seal closure—no moisture needed and a premium security tint to protect sensitive information and a super strong SELF-SEAL strip.
No show of memo, Payee line or amount in windows. Long lasting supply: large sized envelopes and 500 envelopes in every pack for a long lasting supply, perfect for everyday business correspondence and large mailing tasks! Click the Orange Button to order now. Perfect for home or office; securely send checks or other confidential documents.

Stock up on boxes of 500 window envelopes and save; great for bulk mailings, these number 9 envelopes show sender and receiver addresses and can be run through a postage machine.


Our self seal design is quick and easy and is guaranteed to stay sealed with no need for tape or glue sticks.


Double window envelopes show sender and receiver addresses; top window is 1 3/16" x 3 1/2"; 3/8" from the left; 2" from the bottom; bottom window is 1" x 4"; 3/8" from the left; 1/2" from the bottom. 9 mailing envelopes measure 3 7/8 in height x 8 7/8 in width and are made of 24 lb white wove paper with professional side seams; #9 envelopes fit into #10 envelopes.

Privacy: protect confidential client information with our security tinted envelopes. They come in boxes of 500, so you can stock up for long-term use.
Mail invoices, statements and other important documents with confidence. Peel & seal closure: with the peel & seal closure, double window envelopes do not require licking to seal. 500 envelopes in each box: our #9 3 7/8'' x 8 7/8'' envelopes ideal for any document from official business letters to business statement.
1. Amazon Basics
#ad
500-Pack, Amazon Basics #9 Envelopes with Peel & Seal, Double Window, Security Tinted
#adAmazon Basics #ad - Measures 3-7/8 by 8-7/8 inches each. Interior security tint keeps content private; securely send checks, invoices, or other confidential documents. 500-count pack of #9 security envelopes with Peel & Seal closure—no moisture needed.More information #ad
24-pound white wove paper for quality and strength; ideal for home or office. Double window allows sender and recipient addresses to show through.Brand | Amazon Basics #ad |
Manufacturer | Amazon Basics #ad |
Height | 8.8 Inches |
Length | 1 Inches |
Weight | 5.96 Pounds |
Width | 3.88 Inches |
Part Number | amz43 |
Model | AMZ43 |
More information #ad
2. Aimoh
#ad
500 Count 30139, Statements & Documents, 500#9 Double Window SELF Seal Security Envelopes, Size 3-7/8 x 8-7/8-24 LB, for Invoices, Security Tinted
#adAimoh #ad - Long lasting supply; ideal for everyday business use and professional mass mailings, each box of these premium #9 Security Envelopes provide a super long lasting 500 envelope supply, for the best value on the market! Click the Orange Button to order now. Quick seal adhesive; aimoh's #9 envelopes use ultra secure, super secure seal across each envelope’s width that won’t easily open or tear as with cheaper gummed seals, quick seal adhesive to create a full, perfect for larger and thicker documents.Security tint; forget thin, numbers and other data within, easily read envelopes these premium #9 Security Envelopes are designed with security tinted wave patterns which easily obscure details, perfect for mailing business statements and invoices while protecting sensitive information.9
More information #ad
9 double window quick seal security envelopes; tired of cheap thin, with premium security tint, easily torn envelopes? Aimoh's#9 Security Envelopes are the perfect solution, extra large, easily read dual front windows and super secure quick seal adhesive. Double windows; professional, each envelope contains two front windows, eliminating constantly printing and hand writing addresses, easily read double front windows suitable for standard business and legal mailings, advertising campaigns and many more, a 1-3/16" X 3-1/2" top window positioned 3/8" from the left and 2" from the bottom and the bottom 1" X 4" window is 3/8" from the left and 1/2" from the bottom.
Brand | Aimoh #ad |
Manufacturer | Aimoh #ad |
Height | 4.1 Inches |
Length | 11.5 Inches |
Weight | 0.01 Pounds |
Width | 9.2 Inches |
Part Number | FBA_30139 |
Model | 30139 |
More information #ad
3. Blue Summit Supplies
#ad
Designed for Quickbooks Invoices and Business Statements with Self Seal Flip Press and Seal Flap -Number 9 Size 3 7/8 Inch X 8 7/8 Inch, 500 No. 9 Flip and Seal Double Window Security Envelopes
#adBlue Summit Supplies #ad - Quickly and easily stuff our wide envelopes with several invoices or business statements. Perfectly fits quickbooks invoices and business statements: sender and return address will be visible on your QuickBooks invoices and monthly bills through our unique double window design.Save time with easy to use flip and seal self-seal design; With no need for licking or moistening, our self seal design allows for sending hundreds of invoices quickly and easily and is guaranteed to stay sealed with no need for tape or glue sticks.
More information #ad
Provides complete business mail security: your invoices and statements will be completely hidden with our dark security tint design. Maintains professional look and feel throughout transit with our durable 24 LB white wove envelope paper.Brand | Blue Summit Supplies #ad |
Manufacturer | Blue Summit Supplies #ad |
Weight | 5.27 Pounds |
Part Number | BSS-92588-007 |
Model | BSS-92588-007 |
More information #ad
4. HERKKA
#ad
500 Count, Number 9 Size 3 7/8 Inch X 8 7/8 Inch, 24 LB, #9 Double Window Security Envelopes, HERKKA No.9 Double Window Bussiness Envelopes Designed for Quickbooks Invoices and Business Statements
#adHERKKA #ad - Double window design: only sender and return address will show on your QuickBooks invoices and monthly bills through our unique 2 window. Premium security check tint envelopes: the interior of our #9 Security envelopes use a dark navy, offer the protection contents and sensitive information, heavy coverage security tint to provide guaranteed privacy for your legal or business mail, a security tint makes envelopes hard to see through that ensures upmost privacy.Perfectly fits QuickBooks Invoices and business billing statements. 500 pack self seal envelopes:herkka #9 security envelopes are designed with peel & seal closure—no moisture needed and a premium security tint to protect sensitive information and a super strong SELF-SEAL strip.
More information #ad
Quick-seal closure: our #9 envelopes are designed with an ultra strong SELF-SEAL adhesive strip to create a full, super secure seal across each envelope's width that won't easily open or tear, ideal for mailing for any letter sized and larger documents without splitting. No show of memo, Payee line or amount in windows. Long lasting supply: large sized envelopes and 500 envelopes in every pack for a long lasting supply, perfect for everyday business correspondence and large mailing tasks! Click the Orange Button to order now. Perfect for home or office; securely send checks or other confidential documents.
Brand | HERKKA #ad |
Part Number | No9-2Win-Lixing |
More information #ad
5. Columbian
#ad
For Invoices and Statements, Columbian #9 Double-Window Security Envelopes, White, Peel & Seal, 3-7/8 x 8-7/8 Inches, 500 per Box COLO166
#adColumbian #ad - Protect critical documents or your customers' sensitive data; these tinted envelopes have a reflex blue pattern that obscures the details of what's inside. Each #9 envelope is easy to open and close; simply remove the Release & Seal strip and press the flap closed for a clean, sanitary seal; use the pull strip to open without difficulty.Stock up on boxes of 500 window envelopes and save; great for bulk mailings, these number 9 envelopes show sender and receiver addresses and can be run through a postage machine.
More information #ad
Columbian #9 double window envelopes have a patented SimplySafe seal that will show signs of tampering, safeguarding against unauthorized opening. Box of 500 columbian white double window #9 envelopes 3-7/8" x 8-7/8" with a SimplySafe tamper-evident seal and peel off Release & Seal closure; top window: 7/8" x 3 1/2"; bottom window: 1" x 4".Brand | Columbian #ad |
Manufacturer | TOPS Products #ad |
Height | 3.75 Inches |
Length | 12.13 Inches |
Width | 9.13 Inches |
Part Number | COLO166 |
Model | COLO166 |
More information #ad
6. Next Day Labels
#ad
Blackbaud Software ETC, #9 Ready-Seal Double Window Security Tinted Check Envelopes, Box of 500, Sage 100 program, Compatible for QuickBooks Checks
#adNext Day Labels #ad - Fold and seal - Security Tint Inside. Made in the usa by Next Day Labels TM. Box of 500 #9 double window check Envelope, 3-7/8 X 8-7/8. Stop licking envelopes" Just fold the flap, get a quick, secure seal. Guaranteed to fit all your computer business checks.More information #ad
Brand | Next Day Labels #ad |
Manufacturer | Next Day Labels #ad |
Weight | 0.01 Pounds |
Part Number | 6587 |
Model | 92664 |
More information #ad
7. Blue Summit Supplies
#ad
500 No. 9 Double Window Security Envelopes, Number 9 Size 3 7/8 Inch X 8 7/8 Inch, Designed for Quickbooks Invoices and Business Statements with Self Seal Peel and Seal Flap
#adBlue Summit Supplies #ad - Quickly and easily stuff our wide envelopes with several invoices or business statements. Perfectly fits quickbooks invoices and business billing statements: sender and return address will be visible on your QuickBooks invoices and monthly bills through our unique two window design.Our self seal design is quick and easy and is guaranteed to stay sealed with no need for tape or glue sticks.
More information #ad
Provides complete business mail security: your invoices and statements will be completely hidden with our dark security tint design. Maintains professional look and feel throughout transit with our durable 24 LB white wove envelope paper. Just peel and seal to create a strong lasting seal without licking or moistening.Brand | Blue Summit Supplies #ad |
Manufacturer | Blue Summit Supplies #ad |
Height | 4.5 Inches |
Length | 8.5 Inches |
Width | 12 Inches |
Part Number | BSS-92588-002 |
Model | BSS-92588-002 |
More information #ad
8. Office Depot
#ad
White, 9 3 7/8in. x 8 7/8in., Box of 250, Office Depot Double-Window Envelopes, 77166, Clean SealTM
#adOffice Depot #ad - Make mailing labels a thing of the past in your office with these Office Depot envelopes. Includes an office depot clean seal double-window envelopes #9 box of 250 . White double-window envelopes measure 3-7/8" x 8-7/8".More information #ad
Self-adhesive closure keeps the contents safely inside. Windows clearly display return and mailing address. Great for businesses that use check-writing software and computer-generated forms, double-window envelopes clearly display addresses from the inside. Security tint inside provides confidentiality.Brand | Office Depot #ad |
Manufacturer | Office Depot #ad |
Length | 8.88 Inches |
Part Number | MPA/OD/156 |
More information #ad
9. Quality Park
#ad
Quality Park #9 Security Envelopes, 3-7/8 x 8-7/8 Inches, Invoices/QuickBooks Statements, Self Seal, Double Window, 24 lb White, 500/Box QUA24529
#adQuality Park #ad - These boxes of 500 white #9 double window security envelopes 3 7/8 in x 8 7/8 in protect your customers' sensitive data; a reflex blue pattern obscures the details of what's inside.Double window envelopes show sender and receiver addresses; top window is 1 3/16" x 3 1/2"; 3/8" from the left; 2" from the bottom; bottom window is 1" x 4"; 3/8" from the left; 1/2" from the bottom. 9 mailing envelopes measure 3 7/8 in height x 8 7/8 in width and are made of 24 lb white wove paper with professional side seams; #9 envelopes fit into #10 envelopes.
More information #ad
Redi-seal self seal mailing envelopes require no moisture; the unique double flap design allows you to simply raise the lower flap and press to seal. Stock up on boxes of 500 machinable #9 envelopes for bulk mailings.Brand | Quality Park #ad |
Manufacturer | Quality Park #ad |
Height | 3.63 Inches |
Length | 13.13 Inches |
Weight | 5.6 Pounds |
Width | 9.13 Inches |
Part Number | QUA24529 |
Model | QUA24529 |
More information #ad
10. Office Deed
#ad
Office Deed 500 #9 Double Window SELF SEAL Security Envelopes-Designed for Quickbooks Invoices and Business Statements with peel and seal flap -3 7/8'' X 8 7/8''
#adOffice Deed #ad - The liner keeps the gum dust-free before use. Simply press flaps together for a secure, strong seal. . Our products will the perfect fit for all official purpose with high standard quality. Double window: #9 double window envelopes ideal for Quickbooks Invoices, Business Statement, Documents Secure Mailing.Privacy: protect confidential client information with our security tinted envelopes. They come in boxes of 500, so you can stock up for long-term use.
More information #ad
. Wove finish adds a professional touch. Quality: our no 9 security self seal envelopes made of 24-lb white wove. The blue tint pattern makes impossible to see the details of the contents, even when held up to the light. Mail invoices, statements and other important documents with confidence. Peel & seal closure: with the peel & seal closure, double window envelopes do not require licking to seal. 500 envelopes in each box: our #9 3 7/8'' x 8 7/8'' envelopes ideal for any document from official business letters to business statement.
Brand | Office Deed #ad |
Manufacturer | Office Deed #ad |
Weight | 4.43 Pounds |
Part Number | SSEDW9 |
Model | SSEDW9 |
More information #ad