Wednesday, 14 November 2012

What is design for print: DPI & PPI


Definition: 
DPI stands for dots per inch. DPI is a measurement of printer resolution that defines how many dots of ink are placed on the page when the image is printed. DPI does not correspond directly with PPI because a printer may put down several dots to reproduce one pixel. This is because printers use a limited number of coloured inks to reproduce an image consisting of millions of colors. The higher a printer's DPI, the smoother your printed image will appear, provided you have a suitable amount of image resolution (ppi).
Today's photo-quality ink jet printers have DPI resolution in the thousands (1200 to 4800 dpi). They will give you acceptable quality photo prints of images with 140-200 ppi resolution, and high quality prints of images with 200-300 ppi resolution.
The term DPI is often used interchangeably with PPI, causing a lot of confusion, however, DPI refers to the resolution of the printing device, where PPI refers to the resolution of the image itself.


Definition: 
PPI stands for pixels per inch. PPI is a measurement of image resolution that defines the size an image will print. An image that is 1600 by 1200 pixels at 300ppi will print at a size of 5.3 by 4 inches. Or it could be printed at 180 ppi for a printed size of 8.89 by 6.67 inches. The higher the ppi value, the better quality print you will get--but only up to a point. 300ppi is generally considered the point of diminishing returns when it comes to ink jet printing of digital photos.
The term DPI is often used interchangeably with PPI, causing a lot of confusion, however, DPI refers to the resolution of a printing device.

Sources:
http://graphicssoft.about.com/od/glossary/g/ppi.htm
http://graphicssoft.about.com/od/glossary/g/dpi.htm

No comments:

Post a Comment