Adobe Illustrator CC 2015 - Manual (Page 497)

492
Printing
Last updated 6/5/2015
Calculate the maximum blend length for gradients
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.
1 Select the Measure tool , and click the beginning point and the endpoint of the gradient.
2 Note the distance displayed in the Info panel on a piece of paper. This distance represents 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 that occurs within any one color. For instance, take a blend
from 20% cyan, 30% magenta, 80% yellow, and 60% black to 20% cyan, 90% magenta, 70% yellow, and 40% black.
This 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 the relevant maximum
length indicated in the next chart. If it is, reduce the length of the gradient or change the colors.
Number of Steps Adobe Illustrator Recommends Maximum Blend Length
Points
Cms
Inches
10
.3
.762
21.6
20
.6
1.524
43.2
30
.9
2.286
64.8
40
1.2
3.048
86.4
50
1.5
3.810
108.0
60
1.8
4.572
129.6