This is a 24 in. x 12 in. sample of a stone wall. I sculpted the rocks from a styrofoam block using hot wire foam cutting tools, chisels and a box cutter. I roughened the edges of the stones with a stiff brush and textured the faces of the rocks with the brush and other hard tools to scratch, dent and texture the faces of the stones.

I painted the surface with a basecoat bristol brush using foam coat, some model railroad scenery snow to add a grainy texture and acrylic gesso colored with gray acrylic paint. I dripped in some darker gray/black into the cracks between the rocks to darken them.

Once that dried, I painted the individual rocks a lighter gray. I altered the color of some rocks by washing them with a darker black/gray color and made some warmer with a mixture of some warmer yellow and cream hues.

I then used a stiff cleaning brush to flyspeck the stones with various shades of gray, white, black and some warm colors. I left some of them sharper, and toned down some of them using rags or sea sponges to create a variety of texture.

The initial rock wall photo that gave me inspiration had a lot of moss and green discoloration, so I wanted to be sure to wash on some green hues. I dabbed and scumbled some brighter greens in places and broke it up with rags and sponges again where I felt the effect was too strong. I used drybrush to add some highlights and shadows to give the rocks a little more dimension.

Finally, I created a wash with black and burnt umber acrylic and water, then sprayed the whole wall down in places to tie the whole piece together. I let this drip to show more age and weathering.