Yes, it all depends on what type of environment it will be used in. If people are going to be walking up to it then you'll need about 150PPI. 72PPI is fine from a short distance of ten feet or so, and I would never go less than 30 for really huge far away things like 50-foot billboards. 200PPI will let anyone walk right up to it and see a detailed, professional printing job. It just depends if people are going to be able to :) Haha personally speaking knowing that I'd printed something at less than 200ppi would bug the hell out of me so I'd do it no matter what :) I MIGHT go down to 72ppi for a billboard...MAYBE...lol and just a general info-byte for anyone interested in digital printing: There is a difference between DPI and PPI and it matters to a print shop and it's good to know in general. Pixels per inch is the fineness of the digital image. Things on the internet are 72 pixels per inch. High quality prints are 300 pixels per inch. Having more pixels of course preserves much more detail because there are more units to define shapes and lines. This also means you have to render a lot larger or take bigger photos. DPI, dots per inch, has nothing to do with your digital file, only the printer you are using. Inkjet printers use tiny drops of ink, referred to as dots, that make up the pixels in an image. This is why printers advertise say, 1440x2400 DPI. That means that the printer can put down 1440 dots every inch horizontally, and 2400 dots every inch vertically. At 300 dots per pixel, that's about 5x8 dots per pixel, or 40 square dots per pixel. The more dots per pixel there are, the sharper that pixel will be defined in the print. 40 square dots is a lot considering that each pixel is only 1/300th of an inch big. printing at 300DPI would mean only one dot per pixel, making your pixels round and therefor losing the detail of your image.