300dpi is recognized as the most appropriate value, and printed things are the most accurate and beautiful.

More than 300dpi will expose the blank part of PS file too much, but the effect is not good. Less than 300 and the accuracy is not enough, there is a hazy feeling, not fine, not beautiful.

Of course, the difference is not very big. For example, a dpi of 300 or 290 will basically not affect the image quality. Also remember that before printing, the picture format should be saved in CMYK printing mode.