- To get started, open the scanned sketch in Photoshop. Then go to Window > Info to view the Info panel (A in the image below).
- Now, open Levels (cmd-L, or Image > Adjustments > Levels).
- I usually just slide the Black Point (labeled B in the image) toward the middle to make the scanned pencil line darker. (If there is something in the image that you want to be solid black, then you can click the Black Point Eyedropper on it.)
- For the White Point (C), I like to scroll around inside the image to get Info readings for the paper white. My scanner tends to scan white paper at 5 to 6% gray, which I reset to 0 by clicking the White Point Eyedropper on a representative area inside the scan (like the top-right corner of the illustration below). Click OK. Using the White Point Eyedropper is the same as just sliding the White Point Slider toward the middle, but it gives you more control.
- You can use a Levels Adjustment Layer if you want to be non-destructive: On the Layers panel, click on the black-and-white circle (at the bottom), scroll down to Levels.
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| A. (Info Panel) Grayscale value of the point in the image that the cursor hovers over. B. The Black Point, which I slide in toward the middle in the Histogram of Levels. C. The White Point, which I set by clicking on the paper white inside the image. Click to enlarge. |
