The grey stone blocks where given the 5% milk treatment using JoSonja gouache acrylic.I used their Nimbus Grey mixed with a touch of Raw Umber and water.I darkened down the seams using the same mix and a small round brush.Try not to get too much on the face of the stone.
I really like this textured watercolor paper when using thin coats ,as it almost eliminates the need for dry brushing.Remember however one heavy coat and your in trouble.Not all is lost however ,as you can still dry brush the texture back if need be ,using a lighter tint of the same color.This is an example of the great versatility of acrylics.
The grey stones still need a little pastel shading and some crud along the bottom.
I would suggest to those who don't want to go to all this effort to make a brick wall ,if you think it looks good enough for your purposes especially in the smaller scales,when I am finished you could make a copy of the wall and then use photobucket to play with the colors and adjust it to any scale you want.Have fun!
Note: if you want a great tutorial on making scratchbuilt cars or aircraft in brass see my modeling bud Ken Foran's thread over on SMC.He is the best!
Scalemotorcars
Look under Large Scale Cars in the Forum.