When it comes to direct mail marketing and exploring your options, you’re going to be exposed to many different direct mail sizes and formats that you can choose from.

The variety of options can be overwhelming – and when you check out the USPS size requirements, things get even more confusing.

There are also many factors you need to consider when choosing the right type of direct mailer for your direct mail campaign. For example, postcards are perfect for delivering a quick message that drives immediate action, catalogs are designed for recipients to take their time exploring what your company has to offer, and letters inserted into branded envelopes are effective at delivering more personal or private messages.

On top of choosing the right type of mail for your message, you also need to consider your budget, your design, how fast you need your mailers to be delivered, and of course the size and format that best fits all the above factors.

To help you choose the perfect direct mail size, we’ve included everything you need to know on the many direct mail sizes and options that are available to you. Plus, we’ve included design templates to give you a jumpstart on an effective design when you’ve determined the right direct mail size for your goals and budget.

Direct Mail Postcards

Postcards are an extremely cost-effective way to deliver your message and they do not require an envelope, meaning your audience is exposed to your advertisement as soon as they open their mailbox.

These direct mail options are typically printed double-sided on a durable paper stock and have sizes ranging from 4” x 6” all the way to 6” x 11”.

When it comes to mailing your postcards, you need to pay close attention to the format you choose. This is because the USPS has a narrow definition of a “card”: any direct mailer that is at least 5” x 3.5” and no larger than 6” x 4.25”.

What does this mean exactly since many printers offer direct mail postcards as large as 6” x 11”?

Postcards that exceed the maximum size of 6” x 4.25” will be considered letters by the USPS, which have a postage price a few cents higher than that of postcards. While the increase in postage may sound daunting, the increase in size often results in a higher ROI. So, if you’re looking to really grab the attention of your audience or are looking to avoid a small postcard design coming across as cramped and overwhelming, a larger postcard can help you get better results.

Below are the most common postcard options you can choose from when deciding to take advantage of postcards in your mail campaign. You can also view our complete postcard postage cost guide for a more in-depth look into choosing the right postcard size for you.

For help with designing a postcard that follows the printing and USPS design requirements, make sure to download a free postcard design template in your desired postcard size.

Standard or Small Postcard Sizes

Oversized or Jumbo Postcard Sizes

Folded Self-Mailers (Direct Mail Brochures)

Folded self-mailers, also known as direct mail brochures, are the perfect direct mail option that falls in between the postcard and letter. This is because for folded self-mailers, an envelope is not required so they attract that immediate attention a postcard does, but because it is folded, it also can contain more private or more detailed information that is exposed once unfolded.

Folded self-mailers are affordable direct mail options that fall under the letter postage requirements and come in a variety of folded formats including half-folds, z-folds, gate folds, and more. Direct mail brochure sizes also fall under four main categories, two-panel self-mailers, three-panel self-mailers, four-panel self-mailers, and oblong self-mailers.

Below are popular brochure direct mail sizes for you to choose from. To help make the design process easy, download a free brochure template for your chosen self-mailer size.

For more details on the types of brochures and how to choose the right one, check out our blog “Types of Brochure Printing and How to Choose the Right One.”

Two Panel Self Mailers (Bi-fold or Half-Fold Brochures)

Two-panels are the cheapest of the folded self-mailer options and are folded in half providing you with two panels on the outside of your folded self-mailer, and two panels on the inside.

Three Panel Self-Mailers

Three-panel self-mailers are the 2nd cheapest option when it comes to folded self-mailers and can be folded in several ways providing you with three panels on one side when unfolded, and three panels on the other side.

Four Panel Self Mailers

Four-panel self-mailers have several folding styles that all provide you with four panels on one side of your folded self-mailer, and four panels on the other side when completely unfolded.

Direct Mail Catalogs

Direct mail catalogs have one of the highest ROIs, drive higher response rates compared to other direct mailer types, and come with many other advantages. For example, with these multi-paged direct mailers, recipients spend more time looking through them thus strengthening brand awareness and increasing the chances a purchase is made.

Catalogs are often used for promoting greater detail about a company's products or services thus creating a greater connection between the company and the catalog recipient. These powerful mail pieces drive higher sales as well as an increase in web traffic. While catalogs are extremely effective marketing tools, they require the most design time and work due to multiple pages. Because of this, it can be helpful to consult with your printer’s design team to help with your catalog design.

Like all direct mail options, catalogs come in custom sizes. However, below are the most popular sizes for catalogs:

EDDM Mailers

You may be familiar with Every Door Direct Mail, also known as EDDM, which is a low-cost mailing service where you can choose specific "carrier routes” and send direct mail to every address on those given routes. However, it’s important to also know that there are strict guidelines set by the USPS regarding the size/format required to take advantage of EDDM.

EDDM mail pieces can be flat or folded, and each format comes in a variety of sizes you can choose from. Below are popular EDDM direct mail sizes that fall under the flat and folded categories as well as design templates to help you create an EDDM mailer that follows the USPS EDDM design requirements:

Flat EDDM Mailers

Folded EDDM Mailers

Direct Mail Letters

For postage size guidelines, a letter is typically no more than 11.5” x 6.125.” However, the term letter also can refer to a larger direct mail size like a flyer or a message printed on branded letterhead which can also be folded to create a newsletter, a folded self-mailer, or inserted into an envelope.

To increase the effectiveness of your direct mail campaign when using letters, consider using Variable Data Printing to print personalized elements like names, images, or other text that is customized for each of your recipients.

Common direct mail sizes for letters include:

Envelopes

Envelopes can be used to package your direct mail message and can also be included in your direct mail campaign as a return envelope for recipients to reply to your offer or to send in donations.

Envelopes are typically used to contain a more private and personalized message, package multiple materials, or just protect your catalog. The great thing about envelopes is that you can customize them by adding a unique design or even just your logo to help build strong brand awareness.

Envelopes come in several sizes which we have included below. Feel free to take advantage of our free envelope design templates to easily create an envelope that stands out.

Conclusion

With so many choices to choose from, it’s important to become familiar with the direct mail sizes and options listed above so that you can choose the best options that fit your budget while also meeting your goals.

For example, postcards and folded self-mailers are both affordable direct mail formats but depending on your message, a postcard could generate a higher ROI. If you’re still unsure about the direct mail size and format you should choose, contact our direct mail experts today!

Now that you have a better understanding of the many direct mail sizes and options, make sure you check out the variety of mailing services you can take advantage of to successfully deliver your perfect mail piece.