Greeting Card Size Guide for Packaging and Mailing

TL;DR – Greeting Card Size Guide

Choose greeting cards by their finished, folded dimensions. In UK printing, ISO A6 is 105 × 148 mm and ISO A7 is 74 × 105 mm. A 5 × 7 inch card is a separate format, measuring 127 × 177.8 mm. Some US stationery suppliers use A2, A6 and A7 trade labels for different dimensions, so check the measurement before ordering cards, envelopes or packaging.

Greeting cards may look simple, but size plays a major role in how they are printed, packaged, displayed, and mailed. Choosing the wrong dimensions can increase postage costs, create packaging issues, or even cause cards to bend during shipping.

For stationery brands, Etsy sellers, and greeting card businesses, selecting the correct card size helps ensure professional presentation while keeping mailing costs under control. Standard sizing also makes it easier to source envelopes, protective packaging, and retail display solutions.

Whether you are selling handmade cards online or producing custom greeting cards collections, understanding standard dimensions is essential. This greeting card size guide distinguishes UK ISO paper sizes from US stationery labels, explains packaging considerations, and shows how to check envelopes and mailing protection.

Why Greeting Card Size Matters

Greeting card dimensions affect much more than appearance.

Printing Layout and Design

Card size determines how artwork, text, and layouts are positioned. Smaller cards may limit design space, while larger cards allow more detailed graphics and messaging.

Mailing Costs

Card dimensions directly influence postage rates.

Oversized or thick cards often cost more to ship, particularly when using Royal Mail standard letter categories.

Envelope Compatibility

Using standard greeting card sizes makes it easier to source envelopes and packaging materials.

Tight-fitting envelopes can damage card corners, while oversized envelopes may increase movement during shipping.

Retail Shelf Presentation

Card size also affects how products are displayed in retail stores.

Larger cards often stand out more visually, while compact cards are easier to merchandise in high-volume retail environments.

Ask for the finished card dimensions in millimetres, rather than relying on an A-size label alone.

Standard Greeting Card Sizes Explained

About the illustration: The A2, A6 and A7 labels in the image above are stationery trade labels, not ISO paper dimensions. Use the clearly labelled dimensions below when specifying a UK print job.

1. ISO A6 Greeting Cards

Finished dimensions

105 × 148 mm, approximately 4.13 × 5.83 inches. For a folded card, confirm that this is the closed size rather than the unfolded sheet size.

Packaging considerations

Choose an envelope that accommodates the folded card and any inserts. Check the thickness of the complete pack before selecting postage.

2. ISO A7 Greeting Cards

Finished dimensions

74 × 105 mm, approximately 2.91 × 4.13 inches. ISO A7 is smaller than ISO A6; it is not a 5 × 7 inch card.

Packaging considerations

This compact format leaves less space for artwork and messages. Check the complete envelope or mailer against your postal service requirements.

3. 5 × 7 Inch Greeting Cards

Finished dimensions

127 × 177.8 mm. US stationery suppliers may call this an A7 card, but that trade label is different from ISO A7.

Packaging considerations

Select an envelope by its stated internal dimensions and allow room for the card thickness and inserts. A 5 × 7 inch format can provide space for photography, illustrations and longer messages.

US A2 example: Some suppliers sell folded A2 stationery cards measuring 4.25 × 5.5 inches (107.95 × 139.7 mm). ISO A2 paper measures 420 × 594 mm. These are separate sizing systems.

4. Square Greeting Cards

Common Sizes

• 5″ × 5″
• 6″ × 6″

Advantages

Square cards offer:

• modern appearance
• strong shelf appeal
• distinctive presentation

Disadvantages

However, square cards may:

• need envelopes with suitable internal dimensions
• exceed a postal size band once packed
• require a different mailing format if too thick or heavy

Square greeting cards are popular for boutique brands and luxury stationery collections.

5. Slimline Greeting Cards

Dimensions

• Approximately 4″ × 9″

Best For

• Luxury stationery
• Minimalist greeting cards
• Promotional mailers

Slimline cards create a premium appearance and are commonly used for modern or elegant stationery designs.

Greeting Card Size Comparison Table

Source checks: Adobe’s ISO A-series dimensions and Paper Source’s US A2 folded-card example. Always confirm the supplier’s finished dimensions.

Choosing the Right Envelope Size

Envelope Fit Guidelines

Envelopes should always be slightly larger than the folded card.

This prevents:

• bent corners
• surface scratching
• tight-fitting damage

Common Envelope Types

Paper Envelopes

Most commonly used for standard greeting cards.

Kraft Envelopes

Popular for eco-conscious stationery brands and handmade products.

Many brands pair greeting cards with kraft packaging boxes to maintain a natural retail presentation.

Padded Mailers

Used for premium greeting cards or fragile stationery products.

Packaging Options for Greeting Cards

Proper packaging helps prevent damage while improving presentation.

Cellophane Sleeves

Benefits

Cello sleeves provide:

• dust protection
• moisture resistance
• retail-ready presentation

Individual greeting cards are often packaged in protective sleeves before retail display or shipping.

Rigid Mailers

Best For

Rigid mailers are ideal for:

• online orders
• premium cards
• protecting against bending

Why They Matter

Rigid packaging significantly reduces transit damage.

Many stationery businesses use rigid mailer boxes to protect cards during eCommerce shipping.

Greeting Card Boxes

Common Uses

Greeting card boxes are often used for:

• retail display
• boxed greeting card sets
• subscription stationery products

Packaging Features

Popular features include:

• inserts
• dividers
• custom printing

Many retailers use custom retail packaging to improve presentation and shelf visibility.

Mailing Greeting Cards Safely

Tips for Shipping

To reduce shipping damage:

• use protective sleeves
• avoid oversized packaging
• include backing boards for support
• use rigid mailers for valuable cards

Royal Mail Considerations

Measure and weigh the complete, sealed mailpiece, including its envelope, backing board and protective packaging. Royal Mail’s Letter format allows up to 240 × 165 × 5 mm and 100 g. Square shape alone does not determine the postage band: the finished dimensions, thickness, weight and chosen service matter.

Check Royal Mail’s current UK size and weight guidance before posting, particularly for thick, embellished or boxed cards.

Greeting Card Packaging for eCommerce Brands

eCommerce greeting card businesses face additional packaging challenges.

Important Factors

• lightweight shipping
• protective packaging
• attractive unboxing experience

Popular Packaging Choices

Common solutions include:

• kraft mailers
• rigid envelopes
• branded sleeves

Many online brands also use eco-friendly packaging to appeal to environmentally conscious customers.

Common Mistakes to Avoid

Several packaging mistakes can increase costs or damage products.

Common Problems

• choosing non-standard card sizes without checking postage
• using weak packaging materials
• oversized envelopes that allow movement
• insufficient protection for premium cards

Careful sizing and packaging selection help avoid these issues.

Sustainable Packaging for Greeting Cards

Sustainability has become increasingly important in stationery packaging.

Eco-Friendly Options

Popular sustainable solutions include:

• recyclable kraft mailers
• paper sleeves instead of plastic
• FSC-certified board materials

Why Sustainability Matters

Consumers increasingly prefer recyclable and environmentally responsible packaging. Using sustainable packaging can also strengthen brand image and reduce packaging waste. Many brands now choose custom packaging solutions that balance sustainability with product protection.

How to Choose the Right Greeting Card Size

The best greeting card dimensions depend on several factors.

Consider:

• purpose of the card
• mailing costs
• packaging requirements
• retail display needs
• branding and artwork size

Businesses should balance appearance, practicality, and shipping efficiency when selecting card dimensions.

Why Choose Healey Packaging for Greeting Card Packaging

Healey Packaging supports stationery brands with custom packaging solutions designed for greeting cards and printed products.

We offer:

• custom greeting card packaging solutions
• protective mailers and retail boxes
• eco-friendly packaging materials
• custom printed packaging options
• reliable UK packaging expertise

Whether you need retail-ready presentation packaging or protective mailers for eCommerce shipping, our team can help develop packaging tailored to your products.

Greeting Card Sizing & Mailing FAQs

What is the standard greeting card size?

There is no single size for every greeting card. ISO A6 is 105 × 148 mm and ISO A7 is 74 × 105 mm. A 5 × 7 inch card measures 127 × 177.8 mm and should be specified separately.

What size envelope fits a 5×7 greeting card?

Choose an envelope with internal dimensions large enough for the 127 × 177.8 mm card and any inserts. US suppliers may sell this as an A7 envelope; confirm the actual measurements rather than assuming it matches ISO A7.

Do square greeting cards cost more to mail?

Not automatically. Check the finished envelope or mailer’s dimensions, thickness and weight against the selected postal service. A square card can cost more if the complete pack exceeds the relevant limits.

What packaging is best for mailing greeting cards?

Rigid mailers and protective sleeves help prevent bending and shipping damage.

Conclusion

Choosing the correct greeting card size improves presentation, reduces mailing issues, and helps protect cards during delivery.

Whether you sell handmade greeting cards, stationery products, or premium invitation sets, proper packaging plays a major role in customer experience and product protection.

Using suitable envelopes, rigid mailers, and protective packaging ensures cards arrive safely while maintaining a professional presentation.