HVS (High-Grade Vellum Substance) paper is a type of paper commonly used for various purposes, especially in office, education, or printing environments. Over time, HVS paper has evolved to include many different sizes, each with its own function. Here's a brief explanation of the differences between some paper sizes:

- F4 Paper Size F4 paper size is 216 x 330 mm. F4, also known as folio, is typically used for documents that require more space, such as contracts, financial reports, or presentations.

- A1 Paper Size A1 paper size is 594 x 841 mm. This is a large size often used for printing posters, technical drawings, or maps that require ample space.

- A2 Paper Size A2 paper size is 420 x 594 mm. Smaller than A1, it's often used for posters, diagrams, or larger drawings than A3 but still require sufficient space.

- A3 Paper Size A3 paper size is 297 x 420 mm. A3 is double the size of A4, making it suitable for printing posters, diagrams, or documents that require more space.

- A4 Paper Size A4 paper size is 210 x 297 mm. This is the most common standard size used in many countries for everyday documents like letters, reports, and other office documents.

- A5 Paper Size A5 paper size is 148 x 210 mm. A5 is half the size of A4, often used for making notebooks, pamphlets, or smaller and lighter brochures.

- A6 Paper Size A6 paper size is 105 x 148 mm. A6 is smaller than A5 and often used for making postcards, greeting cards, or smaller promotional materials.

- A7 Paper Size A7 paper size is 74 x 105 mm. A7 is half the size of A6 and often used for making small postcards, labels, or other mini documents.

  Each paper size has its specific uses and applications, depending on the needs and preferences of its users.