ISO paper refers to paper sizes defined by the International Organization for Standardization (ISO). Specifically, it's based on the ISO 216 standard, which is an international standard for paper sizes used in most of the world. This system is derived from the German DIN 476 standard.
Key Characteristics of ISO Paper Sizes
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Aspect Ratio: The defining feature of ISO paper sizes is their aspect ratio of the square root of 2 (approximately 1:1.4142). This ratio is crucial because it ensures that if you cut a sheet of paper in half, the resulting two sheets will have the same aspect ratio as the original.
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Series: The most common ISO paper sizes belong to the A series. Other series like B and C exist for different purposes.
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Hierarchy: Each ISO paper size (e.g., A0, A1, A2, A3, A4) is half the area of the next larger size in the same series. For example, A4 is half the size of A3.
The A Series
The A series is the most widely used. A0 is defined as having an area of one square meter. Subsequent sizes (A1, A2, A3, A4, etc.) are derived by halving the previous size. Here are a few examples:
- A0: 841 × 1189 mm
- A1: 594 × 841 mm
- A2: 420 × 594 mm
- A3: 297 × 420 mm
- A4: 210 × 297 mm (the most common paper size for everyday printing)
- A5: 148 × 210 mm
Other ISO Paper Series: B and C
While the A series is the most common, the B and C series serve different purposes.
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B Series: The B series sizes are geometrically between the A series sizes. They are often used for posters, books, and envelopes.
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C Series: The C series is primarily used for envelopes. C-series envelopes are designed to hold A-series papers; for example, a C4 envelope will hold an A4 sheet of paper unfolded.
Benefits of Using ISO Paper Sizes
- Standardization: Simplifies document creation, printing, and archiving.
- Scalability: The consistent aspect ratio allows for easy scaling and resizing of documents without distortion.
- International Compatibility: Widely adopted globally, facilitating international communication and document exchange.
In summary, ISO paper sizes provide a standardized and efficient system for paper dimensions, based on a consistent aspect ratio and hierarchical sizing, making it a widely adopted standard across the globe.
