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International Envelope Series



Belonging to the ISO 216 series, the C6 paper size is a unique and versatile format. It measures 114 x 162 millimeters or 4.5 x 6.4 inches, making it an ideal choice for various applications.

As part of the C series in the ISO standard, C6 is specifically designed to accommodate B6 sheets when folded in half. This compatibility with other formats enhances its utility across different domains.

C6 paper dimensions


View All International Envelope Series

2A046.81 x 66.221189 x 1682119 x 1683370 x 4768
A120.51 x 0.7113 x 181 x 237 x 51
4A066.22 x 93.621682 x 2378168 x 2384768 x 6741
A110.71 x 1.0218 x 262 x 351 x 74
A101.02 x 1.4626 x 373 x 474 x 105
A3+12.95 x 19.02329 x 48333 x 48933 x 1369
A1+23.98 x 35.98609 x 91461 x 911726 x 2591
A0+35.98 x 50.87914 x 129291 x 1292591 x 3662
A64.13 x 5.83105 x 14811 x 15298 x 420
A55.83 x 8.27148 x 21015 x 21420 x 595
A48.27 x 11.69210 x 29721 x 30595 x 842
A311.69 x 16.54297 x 42030 x 42842 x 1191
A91.46 x 2.0537 x 524 x 5105 x 147
A216.54 x 23.39420 x 59442 x 591191 x 1684
A82.05 x 2.9152 x 745 x 7147 x 210
A123.39 x 33.11594 x 84159 x 841684 x 2384
A72.91 x 4.1374 x 1057 x 11210 x 298
A033.11 x 46.81841 x 118984 x 1192384 x 3370

The dimensions of C6 are precisely calculated by taking the geometric mean of A6 and B6 sizes from their respective series. This mathematical precision ensures consistency across all ISO paper sizes and contributes to their widespread acceptance globally.

C6's compact size makes it a popular choice for postcards, envelopes, and brochures. Its dimensions allow it to comfortably house A5 sheets folded into quarters or A4 sheets folded into eighths, providing flexibility in document presentation.

In comparison with ANSI standards prevalent in North America, C6 closely aligns with the U.S.'s 'A2' envelope size but maintains its unique identity through its adherence to international standards.

Overall, the versatility and adaptability of C6 make it a valuable asset in both personal and professional communication contexts worldwide.

Other Formats in the International Envelope Series

Interesting facts about C6

1: C6 Paper Size

C6 paper is part of the ISO 216 standard, which defines the sizes of paper used globally. It measures 114 mm × 162 mm or approximately 4.5 inches × 6.4 inches.

2: Envelope Compatibility

C6 paper size is commonly used for envelopes that can hold A6-sized documents folded in half. This makes it ideal for sending invitations, greeting cards, and small letters.

3: A Series Relationship

The C series of paper sizes, including C6, is derived from the A series. The length-to-width ratio remains constant throughout the series to ensure easy scaling between sizes.

4: Historical Origin

The ISO C series was introduced in the early 20th century by Walter Porstmann and his colleagues at the German Institute for Standardization (DIN). It aimed to standardize paper sizes across Europe.

5: International Usage

C6 envelopes are widely used internationally due to their convenient size for personal correspondence and business communication. They are compatible with both metric and imperial systems.

6: Wedding Invitation Tradition

In many countries, C6 envelopes have become a traditional choice for wedding invitations. Their compact size allows elegant presentation while still fitting within standard mailing requirements.

7: Creative Possibilities

Creative individuals often use C6 paper as a canvas for artwork or calligraphy due to its manageable size. Its dimensions provide a balanced space without overwhelming artistic compositions.

8: Postcard Potential

Cutting a C6 sheet in half results in two A6-sized postcards. This makes C6 paper a popular choice for creating personalized postcards or small promotional materials.

9: Popular Stationery Size

C6 envelopes and paper are commonly found in stationery stores worldwide, offering a versatile option for various writing needs, including thank-you notes, RSVP cards, and short letters.

10: Environmental Considerations

C6 paper can be produced using eco-friendly materials and processes. Choosing recycled or sustainably sourced C6 paper contributes to reducing the environmental impact of paper production.