I use soft chalk for weathering. I use 300 or 400 grade sandpaper and rub the chalk against it. It makes a very fine powder which applies very easily.
I use Bragdon weathering powders. I've used this system for years.. Directly from the Bragdon website: This weathering powder will adhere to any non-glossy surface. It is NOT chalk. One quick step gives a very realistic rusty, dusty or sooty surface - instantly. No drying or curing is necessary. Use sparingly; a little goes a long way. This product is made from real rust and other weathering agents that have been ball milled to a particle size over 100 times finer than chalk and blended with a pressure sensitive, dry adhesive. Self adhesive to most surfaces. Nonmagnetic and Nontoxic. They sell the weathering powders in a kit of 12 powders. A little goes a long way and it adheres to most surfaces. http://www.bragdonent.com/weather.htm Have fun with weathering powders......
Thanks Has anyone used Dr Ben's "new" weathering pigments?? Quite a variety of colours available (eBay). Looks like could be used as a 'paint'
