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First Class “Flats”

The Postal Service uses the word “flats” to refer to large envelopes, newsletters and magazines.

Weights and Sizes

To qualify as a first class flat, envelopes must:

Have one dimension that is greater than 6-1/8 inches high OR 11-1/2 inches long OR 1/4 inch thick
Be no more than 12 inches high x 15 inches long x 3/4 inch thick (for a copy of the Flats Design template, click here: Flats)
The maximum size for a flat provides plenty of room to put lots of material in the envelope. But keep in mind that weight usually affects price – the higher the weight the higher the postage, especially for First-Class Mail.

Is it possible to fold your flat-size piece to letter-size? If so, you can save money because you’ll pay the lower letter price (see more information on First Class Letters here)

Tips for shipping flats-

The font and writing of the address should be proportional to the size of the envelope for easy reading. Don’t use tiny fonts on a large envelope because they won’t be caught as easily.
If the envelope is not bendable because it contains a key, a cd, a book, cardboard, photographs etc… it will be charged a “non-machinable” surcharge and bumped up in class to a parcel.
If you use the manila envelopes with brad enclosures, please tape over the metal. Sometimes (not always) the metal can catch on the postage machine and rip the envelope 🙁

Western Oregon University’s Land Acknowledgement
Western Oregon University in Monmouth, OR is located within the traditional homelands of the Luckiamute Band of Kalapuya. Following the Willamette Valley Treaty of 1855 (Kalapuya etc. Treaty), Kalapuya people were forcibly removed to reservations in Western Oregon. Today, living descendants of these people are a part of the Confederated Tribes of Grand Ronde Community of Oregon and the Confederated Tribes of the Siletz Indians.

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