B4 paper size is part of the B series paper sizes defined by the ISO 216 standard. It measures 250mm by 353mm, or approximately 9.8 inches by 13.9 inches. B4 paper is slightly smaller than A4 paper, which is commonly used in many countries as the standard size for printing and documents.
B4 paper is often used for printing brochures, flyers, posters, and other materials that require more space than A4 paper. It is also commonly used in professional settings for printing business cards, stationery, and other documents. Because of its smaller size, B4 paper is more convenient to carry around and store than larger paper sizes.
Like all paper sizes in the B series, B4 paper has an aspect ratio of 1:root2. This ratio is derived from the geometric mean of the two adjacent A series paper sizes, with B4 being the geometric mean of A4 and A3. This means that B4 paper can be enlarged or reduced by the same ratio as A4 and A3 paper, making it a useful size for scaling documents.
B4 paper is also known as JIS B4 paper, as it is the standard size used in Japan for business documents and printing. It is slightly different in size than the B4 paper used in Europe, which measures 250mm by 353mm, compared to the 257mm by 364mm size used in Japan. Regardless of the regional differences, B4 paper is a versatile size that can be used for a variety of printing and document needs.