To achieve a lithographic effect, try one of the following two methods:
Method 1
-
Image > Mode > Greyscale
- Filter > Sharpen > Unsharp mask (maximum 500, radius 1 to 2, threshold 0)
- Filter > Artistic > Poster edges (adjust / experiment / play)
- Image > Adjust > Threshold (adjust /experiment /play)
Method 2
- Image > Mode > Greyscale
- Lower contrast to give good detail in both shadows & highlights
- Filter > Sharpen > Unsharp mask (maximum 500, radius 1 to 2, threshold 0)
- Image > Adjust > Threshold (adjust / experiment / play)