ABOUT_

72DPI (The Name)

72DPI stands for "72 Dots per Inch"

What is dpi/ppi?

"dpi" means dots per inch (or pixels per inch "ppi") and is used to express the resolution of a screen and measure the density of pixels in an image that is being stored or viewed on a computer.

Digital images are made up of pixels (or dots). Each pixel represents the colour at a single point in the image, so a pixel is like a tiny dot of a particular colour.

History of the term "72dpi"

The term 72dpi goes back to the early Apple computers (Macs). The early Macs were setup to represent points as pixels on screen. Points are the printer's way of measuring type sizes; they are very nearly 1/72nd of an inch. The early apple monitors were designed so that 1 pixel was approximately the size of 1 point, as such Mac programmers got used to points=pixels, hence 72dpi or 72ppi.

The term has continued until today and “72dpi” has become standard industry terminology. It is now common practice when designing for screen based media to create images at 72 dots per inch (or 72 pixels per inch). This concept is carried across other technology with digital cameras and many graphical applications (such as Adobe Photoshop, Adobe Image Ready and Macromedia Fireworks) which have the default resolution for images set to 72dpi.

72dpi today

Unfortunately with advances in technology (changes in screen sizes and resolutions) a resolution of 72dpi (72 dots/pixels per inch) is no longer accurate, but the term and use of 72dpi remains.

Infact the DPI that is used for an image in any screen based media (e.g. a web site) doesn't matter. You could use a 300dpi image or a 2dpi image and get the same result on screen; it's the pixel dimensions set for the image that really count. See the example below.

The only time dpi does make a difference is for text whose font size is specified in points. For example