Step 1: Reset your colours to default (press 'd'). Type whatever it is you want to type in black. Next rasterize the type.
Step 2: Go to Filter -> Artistic -> Coloured Pencil, and set the Width to 4, the Pressure to 8, and the Brightness to 25. Next go to Filter -> Brush Strokes -> Angled Strokes and set the Balance to 50, the Length to 15, and the Sharpness to 3, click Ok.
Step 3: Bring up the Levels Dialog Box (Ctrl + L), and change the Input Levels to 52, 2.99, 150, I got the image on the right.
Step 4: Next Bring up the Curves dialog box (Ctrl + M), and fool around with the colour curves, I got the image on the right.
Step 5: Go to Filter -> Pixelate -> Crystallize and set a value of 10. Go to Filter -> Blur -> Blur More. Go to Filter -> Pixelate -> Fragment.
Step 6: Next Bring up the Curves dialog box (Ctrl + M), and fool around with the colour curves, I got the image on the right.
Step 7: Go to Filter -> Pixelate -> Crystallize and set a value of 10. Go to Filter -> Blur -> Blur More. Go to Filter -> Pixelate -> Fragment.
Step 8: Go to Filter -> Sharpen -> Sharpen More, and then hit Ctrl + F 2 times to run the filter 2 more times.
Step 9: Go to Filter -> Artistic -> Sponge, and set the Brush Size to 2, the Definition to 12, and the Smoothness to 5.
Final Product
Congratulations! Now you have learned how to make a patchy text effect! Below is an example of the finished product.













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