There are many different types of paper commonly used in printing. The following are some of the common categories: 1. Thick classification: According to the thickness of the printing paper, it can be divided into thick paper, medium paper and thin paper. 2. Usage classification: Commonly used printing paper can be divided into printing paper, promotional paper, paper towels, napkins, etc. 3. Material classification: Commonly used printing paper can be divided into raw paper, recycled paper and synthetic paper. 4. Regional classification: Commonly used printing paper can also be classified according to the origin or manufacturing company. 5. Print classification: Commonly used printing paper can also be classified according to different printing methods or uses. For example, the thickness, texture, softness, etc. of the paper suitable for different printing methods are different. These classifications were only a part of the classification of commonly used printing paper. There were many specific classifications that needed to be determined according to the specific usage.