Specifications for Print Image
Images used for print are usually much higher quality and resolution than those used for websites and are consequently much larger files. In general, your images should have a resolution of 150 to 200 dpi for newspaper print and 300 to 400 dpi for glossy print. For high quality commercial print your image resolution will probably need to be as high as 600 dpi.
The recommended file format for print images are Tiff for photos and rectangular image based graphics or EPS for clip art, text based graphics and close cropped images with transparent backgrounds.
Most commercial print companies print on presses that use 4-colour separations – plates that print in four separate colours which when combined on the print material create the final colour blends. This means that images should be CMYK – Cyan, Magenta, Yellow and Black.
Using image editing software the resolution can be changed to 300 dpi, converted to CMYK and saved with the file type appropriate to your needs.
Note: Generally, unless you need to shrink the image, when an image’s resolution is changed to an appropriate print resolution, the pixel dimensions stay the same but the size in inches will change proportionately. Never increase the pixel dimensions of an image and always resize proportionately.