Envelope Size Guide By Type!

Commercial Flap

 

Baronial

Choosing the right envelope size can be tricky, especially when many styles are labeled with numbers instead of dimensions. Whether you’re mailing invoices, sending brochures, or organizing small parts, the right envelope keeps your materials secure and your presentation professional. This guide makes it easy to compare envelope types by size, use case, and available materials.

Regular Envelopes

Regular envelopes are your go-to for everyday business mail. They’re most commonly used for sending invoices, letters, or checks, and are available in multiple sizes. Most don’t have windows and include a simple back flap, with some offering added features like security tint or self-sealing closures.

Other popular regular envelopes include:

• #5 Regular Envelopes (3-1/8″ x 5-1/2″) – Same size as a coin envelope, but side opening. It can be mailed inside of other envelopes or used to store smaller items. This envelope cannot be mailed by itself.
• #6-1/4 Regular Envelopes (3-1/2″ x 6″) – The smallest commercial envelope size available, it’s just the right size for everyday usage; perfect for mailing small items such as a folded personal check. Use to store tickets for an upcoming event or store reminders, coupons, recipes, social security cards, or other items that require organization in your personal records.
• #6-3/4 Regular Envelopes (3-5/8″ x 6-1/2″) – Great for personal or corporate business. This size could be used for invoices, sales pieces, checks, or correspondence.
• #7 Regular Envelopes (3-3/4″ x 6-3/4″) – The ideal model that is suitable for short business correspondence or home office needs.
• #7-1/2 Regular Envelopes (3-15/16″ x 7-1/2″) – It can be mailed inside of other envelopes and used as a return envelope or be used as a mailer for smaller envelopes.
• #8-5/8 Regular Envelopes (3-5/8″ x 8-5/8″) – Popular as business payment envelopes, it is also ideal for checks (no need to fold business-sized checks).
• #9-5/8 Regular Envelopes (4-1/2″ x 9-5/8″) – These are slightly larger than the #9 envelope so it can fit more folded pages.
• #11 Regular Envelopes (4-1/2″ x 10-3/8″) – The larger size allows for more folded pages, storage, and can act as an outer envelope to the #10 envelope being used as a return envelope.

Common Use: Ideal for sending invoices, business checks, and professional correspondence. Often used internally or with reply envelopes for client communications.

Window Envelopes

Window envelopes feature a built-in transparent panel, making it easy to display the address printed on the document inside. These are a great time-saver for mailing invoices or checks and are available in single, double, or full-face window formats.

Common window envelope sizes:

• #6-3/4 Window Envelopes (3-5/8″ x 6-1/2″) – Fits a personal check.
• #8-5/8 Window Envelopes (3-5/8″ x 8-5/8″) – Great for sending check payments from accounting software like Quickbooks.
• #9 Window Envelopes (3-7/8″ x 8-7/8″)– This size fits comfortably inside a standard #10 envelope, so is often used as a return envelope.
• #10 Window Envelopes (4-1/8″ 9-1/2″)– Standard business envelope. Fits an 8 1/2″ x 11″ piece of paper folded in thirds.

Common Use: Optimized for billing statements, financial documents, and check payments where recipient information is visible through the window.

Square Envelopes

Square envelopes are square and symmetrical, appealing to the eye and very stylish. Most square styles have square flaps on the back, but a few have deep triangular contour flaps that nicely offset the square envelope. Sizes range from miniature 5″ x 5″ square envelopes to 13″ x 13″ square envelopes. They are most commonly used with baronial cards for informal mailings, social invitations, and commercial announcements. This type of envelope comes in a wide range of colors, which is great for branding and for invitations to seasonal events or festive occasions. Keep in mind that when mailing square envelopes through the USPS, you will need additional postage because of the shape.

Learn more about the variety of announcement and invitation envelopes we have and their uses on our site >>>

Catalog Envelopes

The main feature of open end envelopes, also known as catalog envelopes, is the placement of the envelope flap on the short end of the envelope. With or without windows, these durable, high-quality envelopes come in brown kraft, white, and bright or pastel colors. With so many options, first select your size and material (paper or Tyvek). Then, select the appropriate closure mechanism: metal clasp, ungummed, remoistening seal, or pressure sensitive seal. There are also clasp envelopes that provide are an alternative to the gum closure. Also, filters in the left column will help you sort for specific needs.

You can choose windowless catalog envelopes or window catalog envelopes. Windowless catalog envelopes ensure that the contents of your package are kept hidden. On the other hand, window catalogs are produced with 28# white sulphite material and have multiple window options so the necessary information on your mail piece can be seen. Catalog envelopes are used for heavy mailing and shipping requirement such as: booklets, bulky documents, catalogs, magazines, sales literature, and more! These envelopes range from 2-1/2″ x 4-1/4″ to 22″ x 27″ to fit any size document.

Booklet Envelopes

Booklet envelopes are designed to accommodate larger and thicker mailings, including annual reports, brochures, catalogs, and sales literature. These envelopes are also ideal for important documents that should not be folded to fit into a standard envelope. They look professional and help to create branding opportunities for your business. These envelopes range from 4-3/16″ x 9-1/2″ to 12″ x 16″ to fit any size document. The 9″ x 12″ booklet envelope is perfect for mailing unfolded sheets of paper. The 5-3/8″ x 8-7/8″ envelope is ideal for mailing a sheet of paper that is folded in half.

One of the biggest decisions you’ll need to make when choosing your booklet envelopes is whether or not to include a window on the front. Some businesses prefer a flat, windowless appearance for these envelopes in order to allow for including a variety of items to be sent and addresses to be printed individually on the envelope itself. However, if you’re planning a big mailing, you can streamline the process by having addresses printed on the document so that it shows through the clear window. Since our booklet envelopes come with such a wide range of envelope window options, including everything from large showcase windows to small corner windows, you can make sure you get a format that’s optimized for your mailing needs.

Remittance Envelopes

Remittance envelopes are designed for collecting payments and donations by mail. Commonly used by nonprofits, schools, and churches, they offer plenty of space for messaging and easy return. Some fit inside standard envelopes for return mail.

Coin Envelopes

Despite the increasing use of digital payment methods, currency in the form of coins and paper money is still very much in use in our society. This style is still made of heavy-duty paper to ensure envelopes can hold numerous coins without buckling under the weight. What has improved over the years is the number of money envelope sizes available. Our money envelope measurements range from #00 to #7H, and we leave it up to you to determine what size works best for collecting monies or other uses.

Despite the name, people find them useful for storing all sorts of little items that would normally get lost or create messy clutter. Consider using these envelopes for storing and organizing items such as nails, bolts and screws, thumbtacks, jewelry beads, stones and metal backing or wires, paper fasteners, small machine parts, seeds, stamps, and numerous other small items.

Specialty Envelopes

Specialty envelopes include designs made for very specific business needs—everything from job jackets to bank deposit slips. They’re often made from heavier-duty materials like vinyl or kraft paper and are ideal for secure storage and niche communications.

Some popular specialty envelopes are:

Need a Custom Envelope?

If our standard envelopes don’t fit your needs, The Supplies Shops can create a custom solution. Choose your ideal size, closure, window placement, color, and material. Fill out our custom quote form or reach out directly to get started.

Click Here to Complete the Custom Envelope Quote Form