What DPI should be used for what situations?

Question

I've been seeing the word 'DPI' pop up quite a lot when I export my work out in Photoshop and Illustrator. While I know that DPI stands for 'dots per inch', and that if you have too low of a DPI on an image, heavy pixellation occurs if you try to zoom in, what would be the optimal DPI for what situations?For example (Situations): - Exporting a print A4 design - Website layout - Logo (Website only - Roughly smaller than the current SE Graphic Design one.) - Logo (Scaling up and down - From business cards to large banners.)

Answer 1

There is a long and short answer for this.

DPI is a printer measurement and not the same as PPI or Pixels Per Inch.

Typically the rule of thumb is if you are printing something >> 300 dpi.

If it's a web graphic or will only ever be presented digitally, 72 dpi is fine.

As most computer screens cannot show beyond that naturally.

However the caveat is that will Apple's Retina screen technology and the various other screen technologies, the pixel density of images is becoming more important.

Retina displays can display 2X the pixel density as regular screens. So it's an moving point of interest in media design.

Here's an article that goes into a bit more detail about DPI and PPI.

http://www.rideau-info.com/photos/whatisdpi.html