Using Help | Contents | Index Back 339
Adobe Illustrator Help Printing
Using Help | Contents | Index Back 339
Calculating the maximum blend length based on the color
change
Adobe Illustrator calculates the number of steps in a gradient based on the percentage of
change between the colors in the gradient. The number of steps, in turn, determines the
maximum length of the blend before banding occurs.
The gradient’s number of steps and maximum length assume that you are printing the file
with a line screen and resolution that produce 256 levels of gray.
To determine the maximum blend length based on the color change:
1 Select the measure tool , and click the beginning point and the endpoint of the
gradient.
2 Note the distance displayed in the Info palette on a piece of paper. This distance repre-
sents the length of the gradient or color blend.
3 Calculate the number of steps in the blend using this formula:
Number of steps = 256 (number of grays) X Percentage change in color
To figure out the percentage change in color, subtract the lower color value from the
higher color value. For example, a blend between 20% black and 100% black is an 80%—
or 0.8—change in color.
When blending process colors, use the largest change between the colors. For instance,
a blend from 20% cyan, 30% magenta, 80% yellow, and 60% black to 20% cyan, 90%
magenta, 70% yellow, and 40% black indicates a 60% change, because the greatest
change occurs in magenta, from 30% to 90%.
4 Using the number of steps calculated in step 3, see if the length of the gradient is larger
than that indicated in the chart. If it is, reduce the length of the gradient or change the
colors.
Number of Steps
Adobe Illustrator
Recommends
Maximum Blend Length
Points Inches Cms
10 21.6 .3 .762
20 43.2 .6 1.524
30 64.8 .9 2.286
40 86.4 1.2 3.048
50 108.0 1.5 3.810
60 129.6 1.8 4.572
70 151.2 2.1 5.334
80 172.8 2.4 6.096
90 194.4 2.7 6.858
100 216.0 3.0 7.620
110 237.6 3.3 8.382
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