While still in an Adjustment Layer Curves Dialog Box, adjust the 1/4 and 3/4 tones. Make sure the value readout is set to Ink Percentage. Make sure the Preview box is checked. Move the 1/4 tone point down and the 3/4 tone point up to increase contrast. Use the Kenly 3•6•9 Rule. You can check and uncheck the Preview box to see the effects of your 1/4 and 3/4 tone adjustments.
The Kenly 3•6•9 Rule gives guidance for adjustments in Curves. Developed by Eric Kenly, the rule states the following:
An adjustment of 3% is a minor correction.
An adjustment of 6% is a moderate correction.
An adjustment of 9% is a major correction.
Any adjustment over 9% suggests that the image should be recaptured.
These percentages work in both plus or minus ranges. Adjustments of +6% or -6% are both moderate.
Move the 1/4 tone point down and the 3/4 tone point up to increase contrast.
Move the 1/4 tone point up and the 3/4 tone point down to decrease contrast. Use the Kenly 3•6•9 Rule. You can check and uncheck the Preview box to see the effects of your 1/4 and 3/4 tone adjustments.
Click OK once you have set the 1/4 and 3/4 tones.
Move the 1/4 tone point up and the 3/4 tone point down to decrease contrast.
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On the next page we will compare the 1/4 and 3/4 Tone adjusted image with the original.
