The World of Modeling I also use ground up pastels with a dry # 5 round brush gently applying to the areas I want to weather. do not push down on the brush,just carefully lay the pastel down,I then blend with a soft shader brush.I add alcohol on the areas where I want it to look like oil or fuel spills.on aircrafts +spaceships I use a pastel pencil sharpened to a very fine point.again applied gently along the panel lines then blend with the shader brush.I seal it with a light coat of clear dullcoat paint.if you add decals its best to seal first with clear gloss coat put on the decals then finish with the clear dullcoat paint.

via what have you found….