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Painting artificial rocks.
By joshua | April 27, 2009
I have had many requests from people asking me about how I paint my rocks.
So here is a summery on the process.
Each rock is different and each type of rock has its own color.
So it pays to use some reference when painting. You want to make sure you don’t paint a piece of granite to look like sandstone.
For these rocks I am using acrylic paints and hand brushes.
The colors I used are.
White, Black, Raw umber, Burnt Sienna, Yellow Ocher, Hookers Green and White pearl.
I didnt use any specific brand of paint, but any waterbased or acrylics will do.
Lets get started!
This set of rocks I cast and arranged for a wall display for a small black bullhead.
Here is a sketch to give you the idea of the finished piece.
The original rocks were molded in silicone, and cast in polyester resin.
I used silicone caulk and will soon post a tutorial on making molds from silicone.
Here are the raw cast rocks, unpainted and arranged.
After the rocks were cast in resin and selected, I cut them to lie flat on my base and then sanded them flat.
They were then glued together with super glue.
I then primed them with a gray primer.
The base coat was then added.
The color used was dictated by the type of rock I was painting.
Beige for the sandstone on the top, reddish cream for the granite, and brown and olive for the other two.
After this was dry I antiqued the rocks by washing them with a dark brown and black.
This is a very thin wash and is brushed on with a soft flat 1/2 inch brush.
The dark color will flow into the low spots and cracks on the surface of the rock.
In the next step I started to define the crystalline structure on the granite and the marbling on the small stone to the left.
To do this I used a small brush and painted the crystals using white pearl, black and burnt sienna.
Don’t be afraid to use metallic paints when painting the rocks, dont go overboard with it, but the extra sparkle adds quite a bit of life.
The small stone on the left is a piece of rounded chert.
For it I used slightly thinned pearl and burnt sienna and black allowing the colors to blend together.
The next stage was drybrushing light highlights onto the surface.
Drybrushing is a technique where paint is applied with very little moisture.
To do this I use a flat brush roughly 1″ wide.
The brush is lightly dipped into the paint then scrubbed off onto a rag until it is almost removed.
It is perfect when you can brush it over your fingertip and highlight only the raised parts of your fingerprint.
I lightly drifted the brush over the surface of the rocks highlighting the surface and softening the colors.
Next I added a light wash of burnt sienna to the granite rock.
This warmed it up giving it a red tone, yet still allowing for your crystals to show through.
Next well the wash was still a little damp I went over the crystals again.
This time with a rather thin application.
This soaks into the damp wash and leaves a nice crinkled effect on the edges of the crystals.
Again using white pearl, burnt sienna, and black.
After this drys thoroughly I washed over all of the rocks with a thinned yellow ocher.
Next I went in and washed black into the cracks and scars of the rocks.
I used a small brush (01 size)
Since this set of rocks is going to represent an underwater scene I decided to replicate a fine layer of algae growing on the surface of the rocks.
For this I drybrushed the surface with an olive green.
I concentrated on the upper surface of the rocks, to replicate the growth of algae from the sun above.
After this the rocks were sealed and are ready to install.
Here are some additional photos.
The backside of the resin rocks.
These techniques can also be used on a larger scale for habitat displays for big game as well as small fish.
There are many many ways to paint a rock, but as with anything follow your references.
In a future blog post I will complete this display and attach the bullhead.
Good luck!
Topics: taxidermy |