A Guide to Pairing Postcards & Envelope Sizes

Ever found yourself struggling to decide which envelope size will work best with your postcard, invitation, or even a flat greeting card? Getting just the right envelope size is not as straightforward as you’d think. It’s not just simply matching the card size to the envelope size. The correct envelope size actually has to do with the size and thickness of the type of card you plan to insert, as well as other items you intend to include in the envelope. We’re here to help you take the guesswork out of choosing just the right envelope size.

First, let’s briefly talk about the difference between Logo Envelopes and Custom Envelopes.

Logo Envelopes can be customized to print on just the front outside surface of the envelope. These are best for businesses who are looking to brand their envelopes on a budget, hence the name logo envelopes. However, they are ideal in scenarios other than just for business. You can print Envelopes with return addresses on them for any sort of correspondence, like wedding invitations or holiday cards. Logo Envelopes start at 25 quantities so it’s perfect for smaller, budget-conscious projects.

Custom Envelopes offers the option of 4/4 printing, which means you can print on both the outside and the inside. So if you’re looking for colorful envelopes and have an intricate design, custom envelopes are your best bet. Custom envelopes start at 100 quantities.

Read on to learn which postcard sizes pair best with which size envelopes.


3″ x 5″ Postcards 
Pair with: Our A1 Envelope* (3.625″ x 5.125″)

or any envelope no smaller than 3.125″ x 5.125″

Shop A1 Logo Envelopes


3.5″ x 5″ Postcards 
Pair with: Our A1 Envelope* (3.625″ x 5.125″)

or any envelope no smaller than 3.625″ x 5.125″

Shop A1 Logo Envelopes


3.5” x 6” Postcards 
Pair with: Our 3.625” x 6.5” Remittance – Long/Short Flap 

Shop Remittance Logo Envelopes | Shop Remittance Custom Envelopes


4″ x 6″ Standard Postcards 
Pair with: Our A4 Envelope (4.25″ x 6.25″)

or any envelope no smaller than 4.125″ x 6.125″

Popularly used for Birthday Invitations, Event Invitations, Wedding Invitations, Wedding Save the Dates

Shop A4 Logo Envelopes | Shop A4 Custom Envelopes


4.25″ x 6″ Postcards 
Pair with: Our A6 Envelope (4.75″ x 6.5″)

or any envelope no smaller than 4.375″ x 6.125″

Shop A6 Logo Envelopes | Shop A6 Custom Envelopes


5″ x 7″ Postcards  
Pair with: Our A7 Envelope (5.25″ x 7.25″)

or any envelope no smaller than 5.25″ x 7.25″

Popularly used for Wedding Invitations, Holiday Cards

Tip: When you send out a wedding invitation, you’re likely going to send an RSVP card and envelope along with it, as well as any additional material such as a details card, or even a sleeve to hold it all together. Putting all these items together does increase the thickness of the set, and therefore could result in a very tight squeeze when it comes to inserting them into an envelope. In this case, we would recommend that you play it safe and order an envelope that’s .5″ wider than your largest print. This way, your entire invitation stationery suite will fit comfortably in the envelope with no fuss.

Shop A7 Logo Envelopes | Shop A7 Custom Envelopes


5.5″ x 8.5” Postcards 
Pair with: Our 6” x 9” Booklet Envelope

or any envelope no smaller than 5.75” x 8.75″

Shop Booklet Logo Envelopes


4” x 9” Postcards 
Pair with: Our #10 Standard (without window)

or any envelope no smaller than 4.125” x 9.125”

Shop #10 Logo Envelopes | Shop #10 Custom Envelopes


We hope this guide was helpful in your search for the best possible envelope sizes for your postcards. While this guide is in accordance with the sizes we offer on GotPrint.com, you can certainly use this as a helpful guide industry-wide.


*At this time, A1 Envelopes and Booklet Envelopes are sizes currently only offered for logo envelopes.

Erina S.

"Those who dream by day are cognizant of many things which escape those who dream only by night." -Edgar Allan Poe

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