What is 300 DPI in a digital file? So, say I have a 6000x4000 pixel digital file, is that 300 DPI? Well, it is if you print it at 20 inches. What if I sent a 600x400 pixel image? I suppose that would be 300 DPI if you printed it at 2 inches. Or, can I just tell my editing software to label said file to call whatever file it saves is 300 DPI even if it is 900 pixels wide.
There is no such thing as DPI until you give the digital file the context of an actual size it will be printed or displayed. (Which, technically, on a computer it would then be PPI and not DPI.)