Traditional Culture Encyclopedia - Photography major - How to make A3 size cover and back cover with PHOTOSHOP?

How to make A3 size cover and back cover with PHOTOSHOP?

Using PHOTOSHOP to make A3-sized front and back covers is:

1. Create a white background file with A3 size (297*420mm);

2. Set the resolution to 300 pixels;

3. Set the color mode to CMYK

4. "File-Save As" JPG file, complete.