A3 paper refers to the international standard A3 paper with a size of 29.7cm×42.0cm, which is also called "Big 8" according to the national paper format industry standard (GB/T 1999). The standard basis of A3 paper comes from ISO2 16. Cotton O2 16 is an international standard of paper size defined by the International Organization for Standardization (ISO), which is currently used in most countries in the world.

ISO2 16 divides the format specifications into a series, b series and c series according to the basic areas of paper formats. The format specification of copy paper only adopts A series and B series, and the size of C series paper is mainly used for envelopes. In national standards, drawings can be generally divided into A5, A4, A3, A2, A 1, A0 from small to large, and the ratio of long side to short side of each drawing is consistent.

Use of a3 paper

1, printing and copying: A3 paper is one of the most commonly used papers in the office. It can be used to print and copy various documents, such as engineering drawings, design drafts, posters, brochures and so on. Due to the large size of A3 paper, it is convenient to display and share information.

2. Painting and hand-drawing: A3 paper size is suitable for painting and hand-drawing, such as sketch, watercolor, illustration, etc. Many artists and designers like to create with A3 paper, because it has high quality and good stability, and can keep the color and details of the picture.

3. Posters and promotional materials: A3 paper is suitable for making posters, leaflets, brochures and other promotional materials. Because of its large size and good printing effect, A3 paper is more eye-catching and plays a better publicity role.

4. Product packaging and labeling: A3 paper can be used for product packaging and labeling. Its larger size can accommodate more information, such as product description, warning statement, brand identity and so on. In addition, A3 paper has high strength and stability, which can ensure the durability of packaging and labels.

5. Calligraphy and handwriting: A3 paper size is suitable for calligraphy and handwriting. Many calligraphers and enthusiasts like to use A3 paper for creation and practice, because it has more space and can display more words and patterns.