Well put, Karl! Basically, if you want to print in a higher DPI, start by rendering in a higher PPI. Your monitor knows nothing of DPI because that's printer talk, and the printer doesn't understand PPI because that's monitor-speak. But if you have an image with large dimensions (like 1280x960) and you're printing to fit within an 8.5x11" paper, you will be printing at a higher DPI than if your image was, say 640x480 to start with. Clear as murk, eh? :)