A6 Paper Size: Perfect for Postcards and Flyers

Small format. Big reach.

The A6 paper size sits at 105 x 148 mm, and it shows up everywhere, from postcards and pocket notebooks to product inserts and print-ready flyers.

Part of the ISO 216 A-series, A6 is half an A5 and a quarter of A4. The math is simple. The applications are not always obvious.

This guide covers everything you need: exact dimensions in mm, cm, and inches, how A6 compares to B6 and US postcard sizes, the right envelope formats, paper weights by use case, software setup in InDesign and Canva, and print-ready file specs including DPI, CMYK, and PDF/X standards.

The A6 Paper Size

What Is A6 Paper Size?

A6 is a standard paper format measuring 105 x 148 mm (10.5 x 14.8 cm, or 4.1 x 5.8 inches).

It belongs to the ISO 216 A-series, defined by the International Organization for Standardization and adopted as the official United Nations document format in 1975. A6 is produced by halving an A5 sheet, which is itself half of an A4. Every size in the A-series shares the same 1:root2 aspect ratio (approximately 1:1.414). This ratio means that halving any sheet always produces two smaller sheets of identical proportions.

ISO 216 is used in almost every country worldwide, with the main exceptions being the United States, Canada, and parts of Latin America (Wikipedia / ISO 216).

Japan defines paper sizes under JIS P 0138, a national standard that mirrors the ISO A-series exactly. An A6 sheet under JIS P 0138 is 105 x 148 mm, identical to the ISO version.

A6 Dimensions in Millimeters, Centimeters, and Inches

The pixel count at 300 DPI is the number you need when exporting a print-ready file. 300 DPI is the industry standard for offset and digital commercial printing, based on ISO 12647-2:2013, which specifies a 150 lines-per-inch halftone screen for coated paper. The 2:1 ratio between image resolution and screen ruling puts 300 DPI as the minimum for sharp results (PrintNinja).

A6 in the ISO 216 Standard

ISO 216:2007 governs the trimmed sizes of writing paper and printed matter for administrative, commercial, and technical use.

The A-series is built on a single principle: A0 has an area of exactly 1 square meter, and every subsequent size is half the area of the previous one.

A6 occupies the sixth position in this sequence. Its short side (105 mm) equals the long side of A7 (74 x 105 mm). Its long side (148 mm) equals the short side of A5 (148 x 210 mm). This relationship holds across the entire series, which is why the scale factor between any two adjacent sizes is always 71% (the square root of 0.5).

How Does A6 Compare to Other Paper Sizes?

A6 is exactly one quarter the area of A4 and exactly half the area of A5.

Folding an A4 sheet in half produces A5. Folding it in half again produces A6. No cutting, no waste. This scaling property is the main practical advantage of the ISO 216 system.

A6 vs A5 and A4

Took me a while to remember this intuitively, but the short side of any A-size is always the long side of the next. Once that clicks, the whole system makes sense.

A6 vs US Postcard and Index Card Sizes

The closest US equivalent to A6 is the standard 4 x 6 inch postcard, measuring 101.6 x 152.4 mm. It is slightly larger than A6 (105 x 148 mm) in both dimensions, but the difference is small enough that many printers treat them as near-equivalent formats for practical purposes.

B6 paper (ISO 216), at 125 x 176 mm, is noticeably larger. B6 sits between A5 and A6 in terms of area and is the format most commonly used for pocket paperback books in Europe.

The international paper sizes system shows just how differently the US and ISO formats approach the same practical problems. Neither is wrong. They just come from different historical starting points.

What Is A6 Paper Used For?

A6 is the standard size for printed postcards, pocket notebooks, compact flyers, and small-format books.

It is compact enough to fit in a coat pocket but large enough to carry a meaningful amount of content. That balance is why it keeps showing up across so many different use cases.

A6 for Postcards and Mailing

Postcards are the most common A6 print application. The format matches the standard mailing dimensions accepted by Royal Mail (UK), Deutsche Post (Germany), and most European postal services.

Direct mail postcards in general have an average response rate of 4.4%, compared to email’s 0.12% (ANA/DMA 2025). Postcards are also 45% more likely to be read than other direct mail formats (Lob State of Direct Mail).

Why A6 works for postcards:

• Fits into C6 envelopes (114 x 162 mm) with no folding
• Qualifies for standard letter postage rates in most European postal systems
• Large enough for a clear image, short message, and return address
• 78% of consumers prefer receiving postcards over other types of mail (Direct Mail Industry Report 2023)

A6 in Print and Publishing

A6 is a common format for pocket-sized paperback books and manga volumes in several markets. Japanese publishers regularly use A6 for manga tankobon (collected volumes), which is part of why the JIS P 0138 standard mirrors ISO 216 so closely.

For print design work, A6 handles well as a format for:

• Product inserts inside e-commerce packaging
• Folded 4-page A7 booklets for instruction sheets
• Small-format catalogs and lookbooks
• Retail shelf wobblers and promotional cards

The global books commercial printing market was valued at $58.46 billion in 2024, growing at a CAGR of 3.6% through 2030 (Grand View Research). A6 book formats contribute to this through pocket editions and manga.

A6 for Stationery and Notebooks

Leuchtturm1917, Rhodia, and Field Notes all produce A6 notebooks. Rhodia’s No. 13 notepad is exactly A6. Leuchtturm1917’s pocket hardcover is A6.

This is the format that goes in a shirt pocket or the back of jeans. A5 is too large. A7 is too small. A6 hits the right middle.

Standard paper weights for A6 stationery:

• 80-90 gsm for writing paper and notepad sheets
• 100-120 gsm for covers and heavier notepads
• 170-350 gsm for postcards and greeting cards

What Is the A6 Envelope Size?

The C6 envelope (114 x 162 mm) is the standard envelope for an unfolded A6 sheet.

C6 dimensions are governed by ISO 269, which defines the C-series of envelope sizes as the geometric mean between the corresponding A and B sizes. A C6 envelope fits an A6 sheet with a few millimeters of clearance on each side.

C-Series Envelopes for A6 Documents

C6 is the most practical for postcards and greeting cards sent without folding.

DL (Dimension Lengthwise) is the go-to for letters and documents where an A6 sheet is tri-folded. DL envelopes are the standard window envelope format used in business correspondence across Europe.

C7 works when space or postage cost is the priority. An A6 sheet folded once fits cleanly inside.

For mailing in the UK, Royal Mail classifies most C6 envelopes as Large Letters, which affects postage cost. In Germany, Deutsche Post applies the Standardbrief rate to letters up to 235 x 125 mm, which a DL envelope fits. Always check current postal dimensions before designing a mailing campaign, since these thresholds occasionally change.

How to Set Up A6 in Design and Print Software?

Set the document to 105 x 148 mm with a 3 mm bleed on all sides, producing a total canvas of 111 x 154 mm.

The 3 mm bleed is the print design standard for A6. It ensures that background colors or edge elements extend past the trim line so there are no white gaps after cutting. Keep critical content at least 5 mm from the trim edge (the safe zone).

A6 Setup in Adobe InDesign and Illustrator

In Adobe InDesign:

1. File > New > Document
2. Set Width to 105 mm, Height to 148 mm
3. Under Bleed and Slug, set all bleed values to 3 mm
4. Keep margins at a minimum of 5 mm from the trim edge

In Adobe Illustrator:

1. File > New > Artboard size 105 x 148 mm
2. After creating, go to File > Document Setup and set bleed to 3 mm on all sides
3. Alternatively, set the artboard to 111 x 154 mm and draw a trim line guide at the 3 mm mark

The live area (where text and logos must stay) is 95 x 138 mm, inside the 5 mm safe zone.

A6 Setup in Canva and Word

Canva: Select Custom Size, enter 105 mm x 148 mm. Canva does not natively handle bleed, so set the document to 111 x 154 mm and manually keep content within the inner 105 x 148 mm area.

Microsoft Word: Layout > Size > More Paper Sizes. Enter Width: 4.13 in, Height: 5.83 in. Word is not ideal for commercial print production, but it works for basic A6 documents that will not go to a trade printer.

For professional print-ready files, InDesign and Illustrator are the correct tools. Canva works for basic jobs. Word is a last resort.

Bleed, Margin, and Safe Zone Specs

Standard A6 print specs:

• Bleed: 3 mm on all 4 sides
• Safe zone: 5 mm from trim edge on all sides
• Document with bleed: 111 x 154 mm
• Live area: 95 x 138 mm
• Color mode: CMYK for all print jobs
• Resolution: Minimum 300 DPI at final print size

What is a bleed in print design and what are crop marks in design are two concepts worth understanding before sending any A6 file to a trade printer. Getting these wrong is one of the most common causes of rejected print files.

How to Print A6 on Standard Printers?

Most home and office printers default to A4 or Letter. A6 requires a few workarounds depending on the printer and the output needed.

Printing A6 on A4 Stock (2-Up Imposition)

2-up printing places 2 A6 pages side by side on a single A4 sheet. This is standard practice in offset printing and works on home inkjet printers too.

Steps for 2-up A6 on A4:

• Set up your A6 artwork at full size in your design application
• In the print dialog, select “Multiple pages per sheet” and choose 2
• Orient the A4 sheet in landscape for a better fit
• Cut down the middle after printing

This approach works for proofing and short-run production. For commercial print runs, most trade printers handle imposition automatically.

Printing Directly on A6 Stock

Most inkjet and laser home printers accept paper down to 100 mm wide, which means A6 (105 mm wide) fits. Check your printer’s minimum media size in the manual or manufacturer specs before loading small sheets.

In Windows, set a custom paper size under Settings > Devices > Printers > Printer Properties > Paper/Quality > Custom.

On macOS, go to File > Print > Paper Size > Manage Custom Sizes and enter 105 x 148 mm.

Paper weight matters. Most home printers handle up to 160-170 gsm without feed issues. Heavier postcard stock (250-350 gsm) typically requires a trade printer with a straight paper path.

The global digital printing market was valued at $38.07 billion in 2023, growing at a CAGR of 6.2% through 2030 (Grand View Research 2024). Short-run A6 jobs are a direct beneficiary of this shift toward digital print production, since minimum order quantities at trade printers have dropped significantly.

What Paper Weight and Stock Is Standard for A6?

Paper weight for A6 depends entirely on the end use. Writing paper and notepads use 80-90 gsm. Postcards and greeting cards need 170-350 gsm.

Paper Weight by A6 Application

GSM (grams per square meter) measures paper weight. Higher GSM means heavier, thicker paper. For more detail on how weight relates to physical thickness, paper weight vs thickness covers the distinction clearly.

Coated vs Uncoated Stock for A6

Coated stock (gloss, silk, matte) has a surface coating that improves ink adhesion and color vibrancy. Best for promotional A6 pieces, postcards, and flyers.

Uncoated stock is more porous. It has a natural feel and is easier to write on. Best for notepads, stationery, and inserts that recipients handle repeatedly.

For a deeper look at how these choices affect the final product, paper finishes explained and uncoated vs coated paper stock are useful references.

FSC-certified and recycled A6 stock is widely available from suppliers like G.F Smith, Antalis, and Fedrigoni. Over 40% of packaging companies have adopted more sustainable print practices as of 2024 (Revenue Memo), and the same shift is happening in small-format print. The global sustainable printing market is projected to reach $3.35 billion by 2030 at a CAGR of 7.5% (Revenue Memo 2024).

Most trade printers (Moo, Solopress, Vistaprint) stock A6 in at least 3 weight options. Moo, for example, offers A6 postcard printing on 350 gsm triple-thick stock as a standard product line. For reference on how different paper types in print design affect finished results, that’s worth reading before choosing stock for a specific job.

What Are the A6 Size Variations Across Different Standards?

A6 measures 105 x 148 mm under ISO 216 and JIS P 0138. Those two standards align exactly, making A6 one of the most consistent paper dimensions across international systems.

The bigger differences show up when you compare A6 to the closest sizes in non-ISO frameworks.

JIS A6 vs ISO A6

Dimensions are identical at 105 x 148 mm.

JIS P 0138 mirrors the ISO A-series entirely. The only place JIS diverges from ISO 216 is in the B-series, where JIS B sizes are calculated as the arithmetic mean (rather than geometric mean) of adjacent A sizes. Japan’s Hagaki postcard standardizes at 100 x 148 mm, which is 5 mm narrower than A6 but shares the same 148 mm height (Japan Paper Sizes, papersizechart.com 2024).

B6 vs A6 for Publishing

B6 (ISO 216) at 125 x 176 mm is the format most European and UK publishers use for pocket paperback editions.

A6 is smaller and tighter. It works for manga and ultra-compact editions. B6 fits more text per page at comfortable reading margins, which is why it tends to win for fiction and non-fiction trade paperbacks.

Key publishing split:

• A6: manga volumes, compact notebooks, short-run pocket editions
• B6: mainstream pocket paperbacks, trade fiction, reference guides

ANSI and ARCH Series Have No A6 Equivalent

Neither the ANSI (A through E) nor ARCH (A through E) series includes a format close to A6 in both dimensions and proportions.

Half-letter (US), at 139.7 x 215.9 mm, is the closest US booklet size, but it is significantly larger and uses a different aspect ratio. Designers working between US and ISO systems regularly hit this gap when preparing A6 documents for North American printers.

How Is A6 Used in Packaging and Product Inserts?

A6 is the default format for product insert cards across e-commerce and retail. The dimensions fit standard mailer boxes without extra folding, and the sheet is large enough to carry a thank-you message, QR code, brand URL, and return policy in readable type.

The global e-commerce packaging market was valued at $77.4 billion in 2024, projected to reach $124.9 billion by 2029 at a 10% CAGR (MarketsandMarkets 2024). Printed inserts are a standard component of this market, particularly for premium and branded packaging segments.

A6 Thank-You Cards and Brand Inserts

72% of buyers say packaging design influences purchase decisions (UPrinting Packaging Statistics 2024).

A6 inserts are the most practical print format for this. They fit inside a standard poly mailer, padded envelope, or cardboard box without adding bulk or requiring a separate fold. Most brands print them on 300-350 gsm coated stock, full-bleed, with spot UV or matte laminate.

Common A6 insert content:

• Thank-you message and brand story
• Discount code for repeat purchase
• QR code linking to product registration or review page
• Return and exchange instructions

A6 as a Folded A7 Booklet

An A6 sheet folded once produces a 4-page A7 booklet (74 x 105 mm).

This is a common format for product instruction cards, warranty guides, and care instructions. A7 is small enough to tuck inside jewellery boxes, cosmetic packaging, and small electronics. Printing it from A6 stock means no custom die-cutting or trimming is needed.

Moo and Solopress both list A6 folded leaflets as standard catalog products, with minimum runs starting at 50 units for digital print.

A6 for Retail Shelf and Packaging Applications

Point-of-sale uses A6 regularly: shelf wobblers, header cards for hanging displays, and countertop tent cards all use A6 as a base format.

For packaging design, A6 also appears as a component of flat-pack product inserts and folded leaflets inside retail boxes. It is compact enough to stay out of the way but large enough to carry the required regulatory text for many product categories. Brands looking at what is a dieline in packaging design will find A6 inserts among the simplest dielines to set up, since the format requires no custom cut shapes.

82% of consumers are willing to pay more for products with sustainable packaging (Trivium Buying Green Report 2023). Brands printing A6 inserts on FSC-certified or recycled stock align directly with that consumer preference.

What Resolution and File Specs Are Required for A6 Print?

300 DPI at final print size is the minimum for any commercial A6 print job. Below that, halftone screening artifacts become visible to the naked eye. The 300 DPI standard is rooted in ISO 12647-2:2013, which specifies a 150 lpi halftone screen for offset printing on coated paper. The 2:1 ratio between screen ruling and image resolution sets 300 DPI as the floor (PrintNinja).

Pixel Dimensions for A6 at 300 DPI

Without bleed:

• Width: 1240 px
• Height: 1748 px

With 3 mm bleed (111 x 154 mm document):

• Width: 1276 px
• Height: 1819 px

Images containing fine text or linework should be prepared at 400 DPI at final size. Commercial offset presses max out around 356 DPI, so anything above 400 DPI produces larger files without quality improvement (PrintingForLess, PrintNinja).

Color Mode and Black Ink Specs

CMYK is the required color mode for all A6 commercial print files. RGB files must be converted before export. Sending an RGB file to offset print causes unpredictable color shifts because the press RIP converts RGB to CMYK using its own profile, not yours.

For how to convert RGB to CMYK in Photoshop, the conversion should happen in Photoshop before placing images into InDesign or Illustrator, not during PDF export.

Black ink on A6 text:

• Body text and small type: 100% K only (pure black)
• Large display type over 72pt: rich black is acceptable (C40 M30 Y30 K100)
• What is rich black in CMYK covers why this distinction matters for registration and ink coverage

PDF Export Standards for A6

PDF/X-1a (ISO 15930-4:2003) requires all fonts embedded, all colors in CMYK or spot, and transparency flattened before export. It remains the most widely requested format by trade printers because it removes file-handling variables (PDF Association, PDF/X in a Nutshell 2017).

PDF/X-4 is the better choice for modern digital printing workflows. It preserves live transparency and supports ICC color profiles, which allows the printer’s RIP to handle color conversion at higher quality. Premier Press and most HP Indigo workflows now prefer PDF/X-4 by default.

For any A6 file going to a trade printer, the print resolution standards and resolution for print vs screen guides are worth reading before export. They cover the practical differences between screen preview quality and actual print output.

Setting up a how to set up a print-ready file workflow from the start avoids the most common rejection reasons: missing bleed, RGB images, and non-embedded fonts. Most trade printers use automated preflight (often based on Enfocus PitStop or Acrobat Pro) that flags these issues before the file reaches the press.

FAQ on A6 Paper Size

What are the dimensions of A6 paper?

A6 measures 105 x 148 mm (10.5 x 14.8 cm, or 4.13 x 5.83 inches). It belongs to the ISO 216 A-series and shares the 1:root2 aspect ratio common to all A-series paper formats.

How does A6 compare to A4 and A5?

A6 is exactly half the area of A5 and one quarter of A4. Fold an A4 sheet in half twice and you get A6. The short side of A6 (105 mm) equals the long side of A7.

What is A6 paper used for?

Common uses include postcards, pocket notebooks, flyers, greeting cards, product inserts, and small-format book editions. It is compact enough for mailing and large enough to carry a clear message with readable body text and imagery.

What envelope fits A6?

A C6 envelope (114 x 162 mm) fits an unfolded A6 sheet. A DL envelope (110 x 220 mm) fits A6 folded in thirds. A C7 envelope fits A6 folded in half. All three are defined under ISO 269.

What is A6 in pixels at 300 DPI?

At 300 DPI, an A6 sheet is 1240 x 1748 pixels without bleed. With a standard 3 mm bleed on all sides, the document size becomes 1276 x 1819 pixels. Always work at 300 DPI minimum for commercial print output.

Is A6 the same as a postcard size?

Almost. The US standard postcard is 4 x 6 inches (101.6 x 152.4 mm), slightly different from A6. A6 is the only ISO 216 size that falls within the US postcard dimension range, making it widely accepted by postal services internationally.

What paper weight should I use for A6?

It depends on the use case. Notepad sheets use 80-90 gsm uncoated stock. Flyers and leaflets typically run on 100-130 gsm coated paper. Postcards and greeting cards need 300-350 gsm board for rigidity and a quality feel.

How do I set up A6 in Adobe InDesign?

Go to File > New, set width to 105 mm and height to 148 mm, then add 3 mm bleed on all sides. Keep content within a 5 mm safe zone from the trim edge. Export as PDF/X-1a or PDF/X-4 for print.

What is the difference between A6 and B6?

B6 (ISO 216) measures 125 x 176 mm, noticeably larger than A6. B6 is commonly used for pocket paperback books in Europe. A6 is the standard for postcards, compact notebooks like Rhodia and Leuchtturm1917, and small print collateral.

Does A6 paper exist in the US?

There is no official ANSI equivalent to A6. The closest US format is the 4 x 6 inch postcard size. US printers can produce A6 using custom paper size settings, and most digital trade printers accept A6 as a standard print format.

Conclusion

The A6 paper size delivers a reliable, internationally recognized format that works across print design, direct mail, packaging, and stationery without modification.

At 105 x 148 mm, it fits C6 envelopes, standard mailer boxes, and home printer trays with equal ease.

Set it up at 300 DPI in CMYK, add a 3 mm bleed, and export as PDF/X-4. That covers 90% of trade printer requirements.

Whether you are printing postcards on 350 gsm coated stock, folding A6 into a 4-page A7 booklet, or producing pocket notebooks for retail, the format holds up.

It is small. Practical. And more useful than most designers give it credit for.

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Bogdan Sandu

Bogdan Sandu is a seasoned designer who has been designing websites since 2008.

Renowned for his expertise in logo design and visual branding, Bogdan has developed a multitude of logos for various clients.

His skills extend to creating posters, vector illustrations, business cards, and brochures. Additionally, Bogdan's UI kits were featured on marketplaces like Visual Hierarchy and UI8.

He also wrote in the past years on sites like Design Your Way, WebDesignerDepot, WPDean, Designmodo, Speckyboy, Slider Revolution, and more.

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