PUB2000: Gradients Printed to High Resolution Printers May Appear Banded (238855)

CAUSE

This behavior can occur if you are using a high-resolution PostScript printer, such as an ImageSetter.

Publisher does not render gradient fills into PostScript gradients. Instead, Publisher uses the Microsoft Windows Graphical Device Interface (GDI) to generate half-tone steps that are then sent to the printer. Depending on the screen frequency (lpi), size of the gradient, and percentage of color used, the banding effect may appear more obvious.

NOTE: Publisher only renders gradients with the Windows GDI for Publisher generated gradients, and non-EPS images containing gradients. All EPS images in Publisher are sent directly to the printer and are not rendered by the Windows GDI. Therefore, this issue does not occur with gradient fills contained within an EPS image.

RESOLUTION

To work around this issue, use one of the following methods:

Create an Adobe Acrobat PDF File

To work around this issue, use Adobe Acrobat Distiller and Adobe Acrobat Reader to print the publication.

NOTE: You can obtain information on Adobe products from the Adobe Web site:

http://www.adobe.com

To print your color publication using Adobe Acrobat:

In Microsoft Publisher, open the publication you want to print.
On the File menu, click Print.
In the Name box under Printer, click the color PostScript printer you want to use.
Under Printer, click to select the Print to File check box, and then click OK.
In the Save in box, click the folder into which you want to save the file.
In the File name box, type a name for the file with a ".ps" extension, and then click OK.
Start Adobe Acrobat Distiller.
On the File menu, click Open.
Locate the .ps file you created in steps 5 and 6.
Click the file, and then click Open.
Type a new name for the Adobe Acrobat Distiller (.pdf) file, and then click Save.
Start Adobe Acrobat Reader.
On the File menu, click Open.
Locate the .pdf file you created in step 11.
Click the file, and then click Open.
On the File menu, click Print.
Click the printer you want to use, select the printing options you want, and then click OK.

Generate the Gradient as a Bitmap EPS

Because Publisher sends EPS images directly to the printer, you can bypass this problem by generating the desired gradient effect using another graphics program. To do this, save the gradient as an EPS graphic file in the graphics program you selected, insert the saved EPS graphic into your Publisher Publication, and then print the publication.

Lower the Screen Frequency (lpi)

You can attempt to lower the screen frequency (lpi) of the printer. This may make the banding problem less noticeable. For information about how to accomplish this task, consult the printed documentation for your printer or contact the printer's manufacturer.

MORE INFORMATION

Publisher uses the Windows Graphical Device Interface (GDI) to render gradient fills for the printer. GDI only has 255 different shades of any given color that it can use from the top of the gradient to the bottom of the gradient. As the lpi of your printing device increases, or the larger your gradient area becomes, or the smaller the gradient range becomes (such as 20% black to white), there are more dots assigned to a specific gradient region, or percentage of fill color. When this happens the human eye can begin to distinguish between the different bands or regions.

For example, if you have a 5-inch long gradient fill (100% black to white), and you are printing to a device at 100 lpi, your gradient is spread across 500 dots. Because there are 255 total shades of black, there are approximately two dots for each shade of black (500 dots divided by 255 shades). Because the bands are so small, the gradient appears smooth to the human eye.

If you change the 5-inch long gradient fill to use 20% black to white, and you are printing to the same 100 lpi device, your gradient is still spread across 500 dots, but because you selected 20% black Windows only has about 50 shades of black to work with (20% of 255 is 51). In this scenario, there are only 10 dots for each shade of black and the overall effect appears banded to the human eye.

REFERENCES

Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information.

The third-party products that are discussed in this article are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.