After being in the graphic design business for over 12 years I have a tendency to take things for granted and forget the struggles of my past. One question that comes up a lot is what resolution to use for different media types. Here is a quick run-down of what I currently know:
- Web: 72dpi (RGB)
- Web: If you develop for 640√ó480 then make your page 600√ó300.
- Web: If you develop for 800√ó600 then make your page 760√ó420.
- Web: If you develop for 832√ó624 then make your page 795√ó470.
- Web: If you develop for 1024√ó768 then make your page 955√ó600.
- Print: varies
- Typical Poster: 150dpi (Typically RGB: 85/100 lpi)
- Newspaper: 150dpi to 200dpi (Greyscale or CMYK: 85/100 lpi)
- Press: 225dpi to 300dpi (CMYK: 133/150 lpi) is the ‘norm‚’ but double check with your printer before starting the job.
- Home Printers: (Typically Greyscale or RGB) This can be a little more difficult to figure out, but once you know the math it’s easy. Just divide the total number of inks your printer produces by the dpi stated on the printer. Example: An Epson printer may boast that it can produce a 1440 dpi image, but you have to divide that by the amount of inks it uses, which is probably 6. That leaves you with 240. This is the dpi you should use on your image for maximum quality. Note: You may get a better image with a higher dpi with some printers.
If you are scanning for a particular job and don’t know how to correctly scan the images, use this page as a reference: http://www.scantips.com/basics03.html. It does a better job explaining than I can. If it is for the web, just use 72dpi, unless there is a possibility it will be used for print later as well.