Question from Dan on another thread about how I did this stonework:
OK, the answer is that it's all a bit trial and error and that I keep going until I get the finish looking about right.
So to start with you have your model wall. I invariably use plasticard and the one above is Wills Coarse Stone which has been abused with files, sandpaper, filler and other sharp objects.
I then give it a coat of Halfords rattle can grey primer. Now, I don't know if this makes a difference but, I generally don't wait for the primer to full dry before overspraying with the base colour coat. For this I have 4 cans (picked up on offer from Hobbycraft about October time):
They are shades of tan (sand), cream (elm), brown (mushroom) and grey (gravel). They were an impulse buy but I like the textured matt finish you can get if breaking every spray rule in the book.
First of all I spray at a distance so that the paint is semi dry when it hits the wall. Then I only give partial patchy coverage to each coat and rotate through using each colour quickly in turn, doing about 3 rotations in total (12 coats in all).
I didn't get a photo of this but here's one of the paper I put down to catch the overspray:
The spraying from a distance means you get a rough textured finish and the use of multiple patchy colours means you get a random colouration. (these are very quick passes with the can, not dumping much paint).
Next I mixed up a thin wash of cream paint and let that run through all the mortar layers. Once that had dried off I turned to using these:
Artists gouache. It's a weird paint as it dries but never really sets and can be reworked by just getting it damp again. I put bits of each colour on a palette and mix up stony colours with the smallest amount of water. Then apply these various colours, almost drybrushed, on to random stones. The aim is to add a bit more colour variation, hints of colour rather than a complete repaint.
Once happy I give it a coat of spray matt varnish so seal the gouache. In this case I gave if another thin wash of the mortar colour. As a final task I treated a few stones to a lick of weathering powder:
I hope that helps. It's not a fixed recipe and I make it up as I go along but using the limited range of colours does mean the results have a family appearance.