Applying chalk as a highlight

[Dave]

I've recently returned to modelling after a 15 year hiatus, and I'm
trying to learn a lot of new techniques at once ! One I would like
some advice on is using chalks as a way of shading military vehicles
(applying chalk to the base of any raised items on the vehicle). I
bought some artists soft pastels, ground some up on a file, and
applied the dust using a brush. However, it doesn't actually do
anything. Could it be I'm using the wrong type of chalk, or maybe the
wrong type of brush (I'm using standard modelling type brushes, that
cost a couple of quid each).

Any advice would be much appreciated.

TIA
Dave

[Lafimprov]

I would advise using chalks as a means of applying realistic dirt and dust
rather than to shadow or highlight the base color (washes and drybrushing,
respectively, are more effective). You should be using regular pastel chalks
rather than oil pastels. If you did use chalk pastels and the colors aren't
"doing anything," either you need to use a color more dramatically different
than your base color (i.e. a dirt color pastel applied to a dirt colored tank
won't be very visible) or possibly you tried overspraying with a flat fixative
coat, which floats the particles off the surface and ruins the effect. Pastels
should be applied last after all oversprays, and not handled afterward. Normal
sable brushes should work fine.
Gerald Owens