if an image is done at 300 ppi, wouldnt any dpi resoultion above 300 dpi be a waste of ink? You won't get a sharper picture, seeing as its the same d/ppi. It you zoome in til you get pixelated, and print it out at a super high printer dpi, it will still look just as pixelated, and no better than if you print it at the actual ppi. Standard commercial prints are 300 dpi. Most print shops won't print any higher, I've asked (this is at least around Montreal). Same with printing text. I know people who swear by printing at 1440 for text... its just text. Unless it's blown up to font zie 200, it won't make a difference. Error diffusion, 300 dpi, glossy paper, fine, and you'll get the same print if you print at 600 dpi... fropm my own personal experience.