This is the suite of previous post about blending modes on Gimp... today while I was drawing with the my pencil series I discovered a curious possibility ... When you change increase drastically the size of the brushes of this series these become very useful for the watercolor techniques.
In this example... based in the Botticelli self-portrait I've set the size brush, Forks | Pencil Color 1, above 500 and the opacity very low, under 40%.
After we need to correct a bit the saturation of colors... this can made with Levels or different layers above the watercolor layer, for instance a layer desaturated with overlay mode.
The pack with these pencils you can download here:
News about this method
Just following the process with pencils brushes I did some new brushes... but a bit large, 256 pixels, mainly thinking in the focus of the stains. When you increase the brush the focus or sharpness is lost.