Gimp Toolbox Series Blur And Shapen Tool

The Blur/Sharpen tool uses the current brush to locally blur or sharpen your image. Blurring with it can be useful if some element of your image stands out too much, and you would like to soften it. If you want to blur a whole layer, or a large part of one, you will probably be better off using one of the Blur Filters. The direction of a brushstroke has no effect: if you want directional blurring, use the Smudge tool