Image Resolution for Printing Made Simple

High resolution images are required for printing, but how high depends on the viewing distance.

But first you need to understand What DPI, PPI and LPI means. (If you know this Skip to resizing images)

DPI means Dots Per Inch (DPCM means Dots Per CM)
In application like Photoshop they use the term PPI or PPCM The First P just stands for Pixels.
DPI tends to get used more often than in PPI in conversations about size of photographs. But in general the following should be used.
DPI - Refers to Dots per inch on printers like inkjets or Imagesetters and DTP Systems.
PPI - Simply refers to Pixels per Inch for digital images and Monitors.
LPI - Which refers to the screening of traditional print like magazines. Often written as oftern 175# or refered to as "Screen Rulling"

This is an example of if you were taking an image to Digital Print, Photo Prints and Canvas Prints.
The Image is viewed at 72PPI on Screen - The image resolution should be set to at least 150PPI - The inkjet printer would be printing at least 2400 DPI  - (LPI is not used because no screen ruling is used).

This is an example of if you were taking an image to Traditional Litho Print.
The Image is viewed at 72PPI on Screen - The image resolution should be set to at least 300PPI - The imagesetter or CTP System will be set to at least 2400 DPI  - The screen ruling for the Images on the printing plate will be between 133# to 200# This is defined by the quality of the paper.

Resizing images

First of all you need to know what the  PPI needs to be for you printed product.

For Fine Art Prints and Magazine prints the PPI needs to be about 300 PPI (120 PPCM Aprox)
For Canvas and Photo Prints the PPI needs to be at least 150 PPI (60 PPCM Aprox)
For Large Posters that are being viewed from a few meters or more then you can go as low as 72 PPI (30PPCM Aprox)

Now if you own a copy of Photoshop then you can constrain the width hight and resolution to adjust your image to the correct resolution for print.

If you don't have photo shop but you know the pixel width and hight of the image then use the sum below
Example of an image that is 3000 x 2000 Pixels

(Please not that for PPCM has been rounded of to the nearest 10 to make the calculation simpler)

For Inches (example for canvas prints at 150 PPI)
x PIXELS ÷ y PPI = z Inches
3000 PIXELS ÷ 150 PPI = 20 Inches
2000 PIXELS ÷ 150 PPI = 13.33 Inches

For CM (example for canvas prints at 60PPCM)
x PIXELS ÷ y PPCM = z CM
3000 PIXELS ÷ 60 PPCM = 50 CM
2000 PIXELS ÷ 150 PPCM = 33.33 CM

If your image is two small then there is some software on the market that will grow your image better that Photoshop.
However when growing an image it does not work to well on jpg images that have lost quality due to being compressed to much.

If you are ordered a canvas print or photo print from us then we can grow your image for Free.