The Smudge tool simulates the effect you see
when you drag a finger through wet paint. The tool picks up color
where the stroke begins and pushes it in the direction you drag.
Select the Smudge tool .
Choose a brush tip and options for the blending mode
in the options bar.
Select Sample All Layers in the options bar to smudge
using color data from all visible layers. If this is deselected,
the Smudge tool uses colors from only the active layer.
Select Finger Painting in the options bar to smudge using
the foreground color at the beginning of each stroke. If this is
deselected, the Smudge tool uses the color under the pointer at
the beginning of each stroke.
Drag in the image to smudge the pixels.
Opomba:
Press Alt (Windows) or Option (Mac OS)
as you drag with the Smudge tool to use the Finger Painting option.
.