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Know Your Envelopes: Part 1

Written by Leslie Nienaber Content Manager

Although you get them in the mail every day and you’ve probably sealed a fair share of them yourself, chances are you haven’t given much thought to envelopes. A good envelope, however, can make or break a message – they can bring about feelings of fear (hello, credit card bills!) or feelings of excitement. As a marketer aimed to stand out above the rest, it’s important to not only be prepared for what goes into the direct mail portions of your campaign, but also know what the best options are for how those messages arrive. In the first of this two-part series, we’ll be addressing (pun intended) some of the different window types available for envelopes.

In the past, window envelopes were mostly used for bills. Lately, they have been used in creative ways for marketing purposes as well. If you are choosing to go with an envelope for your direct mail campaign, the first decision you’ll need to make is whether you want to have one window or two. Using a window envelope is an easy way to let your recipient get an idea of what your message contains while also dispelling fears of bills or urgent business messages.

The most common single window envelope size is 1 ⅛ x 4 ½. The position from the bottom-left may vary, but usually it is around ⅞ from the left and ⅝ in from the bottom.  A single window can display the recipient’s address as well as some teaser copy – be sure to use that space wisely!

Double windows, on the other hand, allow for more room for creativity: use the first window to display the address, and the second window for marketing content, further personalization or a call to action. Double windows vary in size and there aren’t any particular standards set in place, but the most common envelope sizes for double windows are check, #9 and #10 envelopes. 

The material used for the window can be just as important. Here are some of the more common ones:

  • Cellophane: Exceptional clarity, but very expensive.
  • Colored film: Polystyrene film with color added to it. This type is great for creative direct mail purposes!
  • Polyester film: Very durable and high-quality. Many laser printing applications use this type of film since it is resistant to high temperatures.
  • Glassine: If you own an environmentally-conscious business, glassine is a great choice. It’s made of a vegetable-based material with no petroleum products. It’s a bit hazy, but this actually is a benefit when it comes to USPS optical readers where glare can sometimes be an issue. Glassine windows make the entire envelope recyclable.
  • Polystyrene: This is the most popular type of window material, and for good reasons: it resists changes in humidity and is very flexible, so it’s often used in inserting equipment.


At Midwest Direct, our team of experts can help you determine what type of envelope is best for your direct mail needs. Contact us today to get started!

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