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Standard Envelope Sizes & Flap Styles

Stationery Envelopes & Business Envelopes

commercial flap envelopeside seam flap envelopesquare flap envelopewallet flap envelopepolicy flap envelope

No. 10 envelopes (4 1/8 x 9 1/2") are most widely used for both business and personal letterhead and stationery. Choosing which envelope flap is best for your application is a combination of aesthetics and utility.

  • Commercial and side seam envelope flap styles are ideal for  machine insertion.
  • Wallet envelope flaps provide a large area ideal for imprinting.
  • Square envelope flaps have a contemporary look, but are not recommended for most machine insertion.
  • Policy envelope flaps provide a stylish presentation, but are not  recommended for most machine insertion.


commercial flap envelope

Baronial envelopes are easily recognized by their deep pointed flap.Traditional uses for Baronial envelopes are formal announcements, wedding invitations, event invitations and birth announcements.


Baronial envelopes are not recommended for use with automated insertion machines. *These are mini envelopes and are too small to mail. Typical uses include business cards, floral cards, place setting cards and gift cards.


Catalog Envelopes

catalog envelope

Catalog envelopes with a center seam make the envelope more durable for mailing heavy-weight materials. You might consider the Catalog envelope for projects where both a pleasing look and durability are important. You can use these envelopes for face to face sales presentations where you are leaving promotional materials behind and when you are mailing multiple documents and catalogs.


The center seam catalog envelopes can not be processed through inserting equipment and is normally not suited for laser printing.



commercial flap envelope

Announcement envelopes are also known as A-style envelopes or A-size envelopes. The Announcement envelope provides an attractive and contemporary look to envelope projects. Designers use Announcement envelopes for invitations, greeting cards, holiday cards, direct mail advertising, small booklets, wedding invitations, photographs and a variety of promotional and marketing projects.
Sometimes people get confused with Announcement envelope sizes and the common names of metric sized paper A4. There is no relationship between A size envelopes and A size paper.


Booklet Envelopes

commercial flap envelope

Booklet envelopes are commonly used in presenting sales and company information. You may consider using a Booklet envelope for sending or presenting annual reports, marketing brochures, sales materials and proposals. The open side of the booklet envelope makes it suitable for most automatic insertion machines.


It is important to pretest all of your processes, equipment and procedures before producing an envelope mailing. You should pretest all envelopes regardless of manufacturer recommendations for compatibility with automated insertion equipment, printing presses, printing inks, design concepts, envelope contents load and postage costs. Checking with your local post office by presenting an accurate mock-up of your final project will help to determine compatibility and postage costs and is a great way to ensure that you do not receive an unpleasant surprise when mailing your project. By pre-testing and planning you will help yourself avoid problems and errors which may be revealed during your investigations. We recommend that you also plan for spoilage and errors by purchasing 10% to 15% more envelopes than your project requires.