Smudge

The Smudge tool mixes colors by displacing pixels, like a finger passing through wet paint.

 

The basic tool settings are shown in the Tool Options panel above the Image Window. To display the full list of parameters, press the tool icon in the Tool Options panel, or right-click the image. To specify the parameter settings, enter a numerical value in the parameter’s field or use the slider.

Press the Default button to set all settings to their default values.

To spread color along a straight line, first select a starting point by clicking the left mouse button and while holding Shift, move the cursor to the desired endpoint and release Shift. If Shift is not released, then new lines will be drawn to each point where the mouse is clicked.