Operation Manual

433
USING ILLUSTRATOR
Printing
Last updated 11/8/2011
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 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
120 259.2 3.6 9.144
130 280.8 3.9 9.906
140 302.4 4.2 10.668
150 324.0 4.5 11.430
160 345.6 4.8 12.192
170 367.2 5.1 12.954
180 388.8 5.4 13.716
190 410.4 5.7 14.478
200 432.0 6.0 15.240