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International Envelope Series



Belonging to the ISO 216 series, the C3 paper size is a unique and versatile format. It measures 324 x 458 millimeters or 12.8 x 18 inches, providing ample space for various applications.

As part of the C series in the ISO standard, C3 is specifically designed to accommodate B3 sheets when folded. This makes it an ideal choice for creating envelopes or folders that need to hold B3 documents without causing any damage or creases.

C3 paper dimensions


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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 ISO standards are globally recognized and followed by numerous countries worldwide, excluding Canada and the United States which follow ANSI standards. The C3 paper size, therefore, enjoys widespread acceptance and usage across multiple continents.

Interestingly enough, despite its larger dimensions compared to A4 or Letter sizes commonly used in offices, C3 isn't as widely used in everyday printing tasks. Instead, it finds its niche in specialized areas such as professional printing and graphic design due to its ability to comfortably accommodate larger designs without compromising on detail.

In conclusion, while not a common sight in everyday office environments, the C3 paper size holds significant value within specific industries due to its unique dimensions and compatibility with B3 documents according to ISO standards.

Other Formats in the International Envelope Series

Interesting facts about C3

1: C3 Paper Size

C3 paper is part of the ISO 216 standard, which defines the A, B, and C series of paper sizes. It measures 324 mm × 458 mm or approximately 12.8 inches × 18 inches.

2: Envelope Compatibility

C3 paper is commonly used for envelopes that can fit unfolded A3 size documents (297 mm × 420 mm) without any folding or creasing.

3: Architectural Drawings

In some countries, C3 paper is often used by architects and engineers for creating architectural drawings or technical plans due to its larger size compared to standard A series papers.

4: Folding Possibilities

C3 paper can be folded in half to create two C4 sheets (229 mm × 324 mm) or four C5 sheets (162 mm × 229 mm), making it versatile for various printing and document needs.

5: International Business Correspondence

C3 envelopes are commonly used for international business correspondence as they provide ample space for multiple documents while maintaining a professional appearance.

6: Artistic Applications

The larger surface area of C3 paper makes it popular among artists who require more space to express their creativity through drawings, paintings, or other artistic mediums.

7: Historical Origins

The ISO paper size system was first introduced in Germany during the early twentieth century and later adopted internationally as a way to standardize paper sizes across different countries.

8: Efficient Printing Layouts

C3 paper allows for efficient printing layouts as it can accommodate multiple smaller-sized documents, reducing paper waste and optimizing the use of resources.

9: Commonly Used in Packaging

C3 paper is often used in packaging design and production, especially for larger products or items that require more space for labeling, instructions, or branding.

10: Variations Across Countries

While C3 paper is part of the ISO standard, some countries may have slight variations in their preferred sizes or aspect ratios based on historical conventions or regional preferences.