Scanning Tips

Scan at the size of the finished image, not the original.
The ideal situation is to import an image/graphic into the software application with no resizing needed. This preserves the number of dpi (dots per inch) in the image.

 A problem can occur with resizing. If an original scan of 200 dpi is imported and stretched to twice its size, the dpi is reduced by half to 100 dpi. A 200 dpi image will print well, but a 100 dpi will not contain enough dots for clarity and you'll get a fuzzy, unclear appearance.

Conversely, if the same scan is shrunk so that the image is only half its size, dpi is doubled to 400 dpi. The processing time will be considerably more than if it had been imported at 100% and 200 dpi without any improvement in the printed piece because most printing presses cannot process the extra resolution.

A tip for best results: don't scan until the final size of the image is known. Use placeholders in the document before then.

Scan at 1.5 times the lpi (lines per inch) of the printing press that will produce the piece for a good grayscale/color scan or 2 times the lpi for a great scan.
A printing press won't generally be able to process any additional information in a scan that exceeds this limit.

For example, many of our presses at Eagle Graphics, Inc., print at 133 lpi. We therefore scan our grayscale/color photos and images at 266 dpi. Any higher resolution would take more processing time but would not result in a sharper printed image.

Don't save imported photos/images/graphics within the document itself, but link them from the outside.
Images that are cut and pasted into an application can look adequate on the screen, but may not have enough information to reproduce on an imagesetter in a sharp and acceptable manner. It's always a wiser decision to link an image/photo/graphic from the outside.

PageMaker has an option to save an image inside the application rather than link it from the outside. Resist the urge to do so and you'll have a more pleasant design experience!

When an image is saved outside the application and there is a problem with it, it's often possible to go into the original graphic when it's saved in a common format (.tif or .eps). This can also save unnecessary wasted time as the image is returned for customer image manipulation.

Scan line art at 600 dots per inch or more.
Line art consists of entirely black or white pixels. Presses can process much higher resolutions for black/white than for grayscale or color. Modern imagesetters produce resolutions in the 2400 dpi range and above. They can process line art images of 600 dpi, 1200 dpi and above.

Scanned images can be edited, sharpened, maneuvered and changed using image manipulation software.
At Eagle Graphics, Inc., we can perform many different editing operations for you, if you so desire. If you'll need additonal work to your scanned image, please contact your account representative to discuss possibilities.

UNDERSTANDING DPI and LPI -
    Mess this up and a disaster may result

DPI (dots per inch) and LPI (lines per inch) are two important concepts. Understand and use them and you could produce a sharp looking printed product. Or ignore them and you could encounter a horrendous result.

DPI is the measure of how many dots per linear inch a photo/ graphic consists of. The DPI of an image must be high enough to capture the details through shades of gray or colors.

LPI on the other hand refers to the screen frequency of a printer/imagesetter. It refers to how fine a printer can print an image.

Newspapers traditionally print at 85 lpi. Higher quality publications print at around 133 lpi. Higher 4-color presses can print at 150 lpi or higher.

But here's the catch! Typically, a printer/imagesetter cannot process grayscale/color DPI information of more than 2 times their LPI.

That is, an imagesetter that prints at 133 lpi can only process photo/ grayscale graphic information to a maximum of 266 dpi. Any DPI over that is wasted, taking up memory and space but adding nothing appreciable to the final product.

Therefore, scanning a grayscale/color image at 600 dpi when the imagesetter is only printing at 133 lpi is wasting your time, money (since it takes longer to process and print) and is trying the patience of those associated with the job.

For example, if the printer/imagesetter will output at 133 dpi, scan somewhere around 200 (for a good scan) to 266 (for an excellent scan). If the printer/imagesetter only outputs at 106, scan between 150-200 dpi.

Solid black/white graphics can and should be scanned at higher DPIs. Since b/w graphics do not deal with shades of gray, higher DPIs will produce sharper images.

In conclusion: when scanning a grayscale/color photo or image, always determine the LPI of the printer the piece will be printed on. Scan at the DPI 1.5 (for good) to 2 (for excellent) times its lines per inch.