I want to ask people who are good at calligraphy how to choose a writing brush.

Actually, your previous reply was quite right. It depends on what style you learn. If you have just started to learn calligraphy or use double brushes, it is more appropriate and easier to master it. If we start with open letters and official documents, the front will be shorter. If it is thread or grass, the front will be a little longer. In addition, the elasticity of the pen is also very important. But the price of a better brush is a bit expensive now.