In the Paint Panel or Brush Options window set Blur Strength.
By default, the Blur brushes have a Blur Strength value of 3.0. You may want to increase the Blur Strength to make the image or strokes less defined, or reduce the Blur Strength to add just a touch of blur (perhaps to get rid of some JPEG artifacts in an imported image).
In the Paint Panel or Brush Options window, adjust the Blur Strength slider or enter a value in the Blur Strength field.
See also Blur paint.
