Technical Illustrators.org Forum

Hi All,

Is there such as thing as standard resolutions for particular mediums? For example, 72dpi for screen, 300ppi for most printers, 1200ppi for colour separations... I am wondering at what resolution should I be drawing at if the client doesn't tell me or doesn't know themselves where the illustration will end up, such as in a website and printed on a brochure. Does anyone have any guidelines for this?

Good questions. My only advice is build in a high resolution: 300 dpi, which works for most commercial printers. It's easier to "dump" information when down-sizing than it is to bring it back when up-sizing.

To be technical (and that's what we do here) you're talking about pixels-per-inch (PPI) not dots-per-inch (DPI). PPI refers to the density of information in an image file, whereas DPI refers to the density of ink/toner dots on a printed page. The two are commonly used interchangeably, but it's useful to know one describes the amount of information in an image, and the other describes the precision of a printer or output device.

These numbers only mean something when paired with a specific size. For example an image that's 2400px by 3000px could be 72ppi, 300ppi or 1200ppi. But if it's printed at 8" x 10", it'll be 300ppi.

To answer the question though, in general, images for the web are produced at 72ppi, for print at 300ppi, and for large scale printing around 100-150ppi. That's not to say that every screen displays images at 72ppi, or every printer prints at 300ppi, these are just common practice because they produce good-enough results without excessive file size.

I typically produce my raster work (Photoshop, 3D, etc) 50% larger than the client asks for (so 450ppi at the given print size). I do this to squeeze in more detail, in case the client wants to use it larger, or in case I want to resell the work later or print it myself. Like Matt said, it's always possible to scale images down, but never up.

Hope that helps!