Graphics that are created by a paint program, a scanning program, or a digital camera are made up of a grid of differently colored squares called pixels. The more pixels a graphic has, the more detail it shows.
The resolution of a picture is expressed in pixels per inch (ppi). Every picture has a finite number of pixels. Scaling a picture larger decreases the resolution (fewer ppi). Scaling the picture smaller increases the resolution (more ppi).
If your picture resolution is too low, it will be printed more blocky. If the picture resolution is too high, the file size of the publication becomes unnecessarily large, and it takes a longer time to open, edit, and be printed. Pictures with more than 1,000 ppi may not be printed at all.
If the resolution of the picture is greater than what the printer is able to print (for example, an 800-ppi picture on a 300-ppi printer), the printer takes more time to process the image data without showing any more detail in the printed piece. Try to match the picture resolution to the resolution of the printer.
Color pictures that you plan to have printed by a commercial printer should be between 200 and 300 ppi. Your pictures can have higher resolution — up to 800 ppi — but they should not have a lower resolution.
NOTE: You sometimes may see picture resolution expressed as dots per inch (dpi) instead of ppi. These terms are often used interchangeably.
A picture contains the same amount of information whether you scale it larger or smaller in your publication. If you want more details in your picture to appear as you enlarge it, you need to start with a picture that has a higher effective resolution.
Every picture in your publication has an effective resolution that takes into account the original resolution of the graphic and the effect of scaling it in Publisher. For example, a picture with an original resolution of 300 ppi that has been scaled 200 percent larger has an effective resolution of 150 ppi.
To find the effective resolution of a picture in your publication, do the following:
- On the Tools menu, click Graphics Manager.
- In the Graphics Manager task pane, under Select a picture, click the arrow next to the picture, and then click Details.
- In the Details window, the Effective Resolution field displays the resolution in dots per inch (dpi).
Reducing high-resolution graphics
If you have just a few graphics whose resolution is too high, you may have no problem printing them. If you have several high-resolution graphics, your publication will be printed more efficiently if you reduce their resolutions.
IMPORTANT: Before you reduce the resolution of a graphic, consult with your commercial printing service about the resolution that you need.
In Publisher, you can reduce the resolution of one, several, or all pictures by compressing them.
- In Publisher, select one or more pictures whose resolution you want to reduce, right-click one of them, and then clickFormat Picture.
- In the Format Picture dialog box, click the Picture tab.
- Click Compress.
- In the Compress Pictures dialog box, under Target Output, click Commercial printing.
- Under Apply compression settings now, choose whether you want to compress all pictures in the publication or only the pictures that you selected, and then click OK.
- If a message appears asking if you want to apply picture optimization, click Yes.
A 300-ppi version of the same picture or pictures replaces the high-resolution original picture or pictures.