Top 12 Square Flap Envelope Templates to Try

Choosing the right envelope is crucial to sending the right message. It is the first thing the eyes see when receiving a letter and as they say, “first impressions last”. 

There are several types of envelope flaps. Pointed envelopes are the classic, go-to envelopes for greeting cards, stationery use. Commercial flaps meanwhile convey utility as they are mostly used to send bills, credit card statements and more. There are also rectangular flaps, the straight and square flap. The square flap envelope has a longer seal length compared to the straight flap envelope.

Square flap envelopes are the main style for invitations and greeting cards. They are modern and elegant. Square envelopes can hold many enclosure cards when made with the right construction materials. It provides a larger area for invitation designers to work with, which is why it is the perfect choice for wedding announcements.

Here are 12 square flap envelopes you should try.

Mini-lope Envelope 

These are 2.125” x 3.625” envelopes. This size of envelopes is also called drug envelopes for their use in prescription medicine.


A2 envelopes are 4 ⅜” x 5 ¾” and the cards inside are sized at around 4 ¼” x 5 ½”. These are commonly used for RSVPs and mailing cards because they fit inside other larger sized envelopes. A guest has to return the RSVP card for confirmation and so including an A2 envelope inside your bigger invitation envelope can be convenient.


A6 is bigger than A2 at 4 ¾” x 6 ½”. It can still fit larger “A” envelopes but it allows for a wider space to write on.  The card insert should be at 4 ⅝” x 6 ¼” at most. This size is perfect for designers to work on because there is just enough space that doesn’t require minimalism like a mini-lope envelope.


For invitations and announcements that want to include 5” x 7” photos, this is the perfect square flap envelope template for you. These are 5 ¼” x 7 ¼” in size whose card should be 5” x 7” at most. It is most suitable for including smaller enclosure cards or envelopes like A, A1, A2, and A6.

#5 Square Envelope

As the name suggests, this envelope is 5” x 5” in size. Not only is the flap square, but so is the actual size of the envelope. A card of 4 ¾” x 4 ¾” would fit perfectly inside this size of envelope.

#6 Square Envelope

Just like the previous type, this is a square envelope at 6” x 6”. This size is ideal for holiday cards and baby showers. They are larger than greeting cards but provide just enough space for announcements. They are not as bulky than bigger sized square envelopes that typically include other cards or photos.

#7 Square Envelope

Square flap envelopes of this size and larger come with a number of enclosure cards more often than not. A 7” x 7” envelope is enough to include main invitations, reception card, accommodation card, and RSVPs. The inclusions should be around 6 ¾” x 6 ¾” to sit comfortably inside.

#8 Square Envelope

At this size you can add a card for rehearsal dinner and post-wedding events arrangements to the previously mentioned list of enclosure cards. With this much cards however, you should take note of the paperweight size that is appropriate to hold the weight of these contents. Use 7.5” x 7.5” cards if you want to include more than 5 enclosure cards in your envelope.

#9 Square Envelope

These 9” x 9” square flap envelopes are sure to stand out in your recipient’s mails with its large size and sleek design. The look just screams “important” and “VIP” that your guest won’t help getting their hands on the contents right away. They often require additional postage, but there’s so much room to design your invitations with this size that makes it just worth it.

#10 Square Envelope

This template is 4 ⅛” x 9 ½”. It is not as square as the envelopes just mentioned but still quite large. Your choice for square envelope size should keep up with functionality as is the case for this design, which is bold and daring. 

One way to not overwhelm your recipient with this envelope is design the outside with embossed text or line it with metallic colors. Use 9.5” x 9.5” papers or smaller to fit as many cards as possible. You can also opt to include a see-through or window at the back of the envelope to give a peek into the contents of your envelope.


This square envelope size is distinguishably longer than other envelopes at 3 ⅞” x 7 ½” or 4” x 7 ½”. It is ubiquitous in stationeries and can be interchangeable between longitudinal and horizontal. It gives more space for creativity. 

The flap of a monarch can be placed on the top fold or the side fold making it a versatile design. The insert card should be around 3 ¾” x 7 ¼”. Thrice-folded invitations are perfect for this envelope size.


Compared to #10, A10 is slightly taller at 6” x 9 ½”. The enclosure should be around 5 ¾” x 9 ¼”. This requires no extra postage compared to other large envelopes. At this size you can choose not to fold your announcements. This way your invitation will look picture-perfect without the creases and will remove smoothly when read by your guests.

Square flap envelopes are classic and contemporary at the same time. Making your own square envelopes are easy as getting the right template and following the right guides to cutting and folding your materials. Just make sure to get the best materials that can hold your documents, invitations, and other enclosure cards. 

There’s so much room for creativity with square flap envelopes, from inserting wordings on the flaps to gilding the folds. Making square flap envelopes should be a breeze with the best templates. Have fun creating your envelopes!