@yabieru: Actually, there is no pixel size associated with the 'real life' dimensions of cm/mm/inches. It depends on the resolution of the image. If, for example, I have a 2480 x 3508 px image with resolution of 100 pixels/inch, the document size ends up being about 24x35 inches. The best thing is to not worry about that too much and let me do resizing.
As long as the proportion is fine and the pixel dimensions aren't too small, it's fine. ^^
As for the title, I guess it's fine, np! ^^