Adobe Illustrator CS4 User Manual
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USING ADOBE ILLUSTRATOR CS4
Web graphics
GIF image with 0% dither (left), and with 100% dither (right)
You can select one of the following dithering methods:
•
Diffusion
Applies a random pattern that is usually less noticeable than Pattern dither. The dither effects are
diffused across adjacent pixels.
•
Pattern
Applies a halftone-like square pattern to simulate any colors not in the color table.
•
Noise
Applies a random pattern similar to the Diffusion dither method, but without diffusing the pattern across
adjacent pixels. No seams appear with the Noise dither method.
Transparency and Matte
Determines how transparent pixels in the image are optimized.
•
To make fully transparent pixels transparent and blend partially transparent pixels with a
color, select
Transparency and select a matte color.
•
To fill fully transparent pixels with a color and blend partially transparent pixels with the same color, select a matte
color and deselect Transparency.
•
To select a matte color, click the Matte color swatch and select a color in the color picker. Alternatively, select an
option from the Matte menu: Eyedropper Color (to use the color in the eyedropper sample box), Foreground Color,
Background Color, White, Black, or Other (to use the color picker).
Note: The Foreground Color and Background Color options are only available in Photoshop.