I am working on A0 size posters. the client gave me the image of size 59x39 in (72dpi). i changed it to 300dpi and therefore the size came down to 14x9 in. According to my design the image covers 85% of the poster space. My question is: Is it ok to scale up the image from 14x9 in to 6 times its size. is it ok to do that or is there anything else that I should be doing?