The rules of thumb for adjusting the Dot Gain:- If the printed image looks lighter than your screen
display, as in this example, nudge the Dot Gain value
down by pressing the � key. - If the printed image appears darker than your screen
image, raise the value by pressing the � key.
Small changes result in significant adjustments, so give
the screen a moment to refresh between each press of the
� or � key. I found that a Dot Gain value of 22 percent
provides a pretty close match.
- Choose Curves from the Dot Gain pop-up menu. The
problem with adjusting the Dot Gain value is that it
lightens or darkens all color channels at once. So while
the brightness of the screen image roughly matches the
output in Figure 12-14, on page 487, the reds don’t ap-
pear washed out enough. To adjust each channel inde-
pendently, choose the Curves option from the Dot Gain
pop-up menu (see Figure 12-19). Photoshop responds
with the Dot Gain Curves dialog box. - Adjust the Dot Gain Curves values for each channel. If
the All Same option on the right side of the Dot Gain
Curves dialog box is checked, turn it off. Use the Cyan,
Magenta, Yellow, and Black options to switch between
the four color channels and modify their luminosity val-
ues independently. This lets you correct the colors of the
CMYK screen display one ink at a time.
To keep things as simple as possible—and by my reck-
oning, we could dearly use a bit of simplicity right about
now—I modified only the 50 value for each channel. As
shown in Figure 12-20 on the next page, I lowered the
values for the Cyan, Magenta, Yellow, and Black chan-
nels to 70, 66, 70, and 72, respectively.
Figure 12-19.PeaRl Of WISDOmYou might well ask how I arrived at these values. To which I would answer—as I so
often do—trial and error. But to shed some light on my reasoning: Lower values
lighten the screen image to bring it more in line with the CMYK output. Pressing �
lowers a value in increments of 0.1 percent; more useful, Shift+� lowers a value by
a full 1 percent. Using Shift+�, I lowered the Cyan and Magenta values by roughly
equal amounts (18 and 19 percent, respectively). I lowered the Yellow and Black values
by smaller amounts (15 and 13 percent, respectively) to keep more yellows and blacks
in the image, which I found necessary to match the color balance of the output.
Preparing a CMYK File for Commercial Reproduction 439