First plant A4 size (2 1CM*29.7cm) with the cropping tool, and then find the resolution setting in "Image" and "Portrait Size" in the toolbar. The higher the resolution setting, the larger the file. You can change the file size by reducing the resolution appropriately. For A4, a resolution of 600 to 1000 is enough. In order to ensure that the quality is not affected and the completed file is not destroyed, it is saved as a jpg image in save as mode. If the file is still too large, it will become smaller if it is changed to the JPG format of Wed.