This painting tutorial is designed with the beginner in mind, but is intended for all. I plan on updating from time to time as I find new and better ways of making plaster stone look real.
New England Brownstone is interested in our customers being more than pleased with their purchase and we want you to feel comfortable with painting our castings. We don’t want you to feel intimidated by the examples that we have on our site. They were all fairly easy to do. With these techniques a few simple tools you will be able to crank out the best looking stone walls that’ll knock any judge’s socks off. We want all of our customers to end up with excellent results, every time.
Very few books about painting models deal with stonework, or if they do it is at best for a generic application. Simply painting a wall with a base color and then applying an India ink wash really doesn’t do the job. It works OK, but if you really want to make a casting come alive and depict a certain region of the country, then you need to read on.
A quality paint-job is not that hard to do if you have the visual resources.
Observing the real world
The biggest help is arming yourself with photographs of the wall you are trying to depict.
As modelers we have a tendency to assume too much. In real life stonewalls are not simply one color, but are a conglomeration of different earth tones that result in a mottled look. This mottling is just natural color variations in the stone and can be fairly subtle and be of one dominant color, but with variations in shade. This is what we like to refer to as the base coloring. Base coloring is not a complete paint job, but one step and under most circumstances consists of only two, or three colors that we’ll be concerned about, neutral gray and iron oxide brown, or burnt sienna. The neutral gray is used in all of our wall painting, but the locale of the wall will determine what browns to use. Varying between the gray and the browns two will cover most stone coloring requirements. Specific stone colors will be dealt with in subsequent clinic pages.
Check out the reference picture page on our site for ideas. Look at the stone coloring closely and you will see variations of grays and browns and even hints of green (from fungus). Notice the weathering and staining and how wet areas look in real life. We’ll expand on these areas and treatments farther down, but for right now we’ll concentrate on some more of the basics.
Let’s take a look at some examples to get a better idea of what some real walls look like. You can see more real stone walls here.
The following is the basis for all of our stone wall painting, although sealing and colors may be changed depending on what the modeler is trying to duplicate. Steps to create a particular type of stone will be handled in separate clinics.
Our technique is a five step process
1. Sealing (sealing is dependent)
2. Base (sponge application)
3. Fill (independent stones)
4. Joint darkening
5. Specific treatment (weathering and natural staining)
Step 1. To Seal or Not to Seal
This is not so much a step, but a technique that should be used for certain types of stone. When we refer to sealing we mean only to dust the casting lightly with a clear polyurethane sealant. You don’t want to coat the casting as if you were trying to paint it. Sealing does two things. 1. It prevents the paint from being absorbed into all of the plaster at once, which helps create the mottled effect and it allows more time to work. 2. It seems to make the colors a bit more vibrant, depending on the base color.
For example, we use it to create the look of light colored granite.
These are pictures of the back (smooth side) of a casting that was sealed (dusted) with clear polyurethane spray with a gray wash applied. Notice how nicely it creates the look of polished granite. The casting on the left is very close to real gray granite and by adding a small amount of iron oxide or russet to the wash the plaster begins to look like tan or pink granite (right).
This does not mean that we seal every time. Sealing is dependent on what type of stone you are trying to replicate. There is natural stone, sandstone for instance, that is best represented by not sealing thus giving the plaster a flat look.
Step 2. The Base
Unless you are a glutton for punishment you don’t want to paint each stone individually. This can produce great looking stone work, but it is way too time intensive for the average modeler. Also, in an attempt to be random the modeler has a tendency to make the wall look like a checkerboard. Better and more natural results can be had using our techniques.
It creates an effect similar the leopard spot method except that instead of painting individual stones with a brush we use a sponge. Sponges have the distinct advantage over a brush because they can carry a load of paint and apply it to a large area very quickly and the openings in the sponge leave blank areas on the castings that don’t get painted, this helps create varying shades of the color being applied by overlapping during subsequent applications. These blank areas will eventually be filled in by the sponge over the casting a multitude of times, thus creating a mottled effect. You want to use the sponge in a rolling motion to prevent “tiling” or repetitive patterns. See following photos.
By vary the colors slightly during this step will help randomize the overall coloring of the wall.
The Rolling Technique used with a sponge for application. Remember to rotate the casting to prevent “Tiling”. We use a rolling movement to prevent tiling of pattern, which is what would happen if you simply use the sponge like a stamp. If you have to use the sponge like a stamp, apply light pressure and rotate the sponge after each application. It doesn’t have to be much. We just don’t want to create any repetitive patterns. As for sponges, you can use either natural real sponge or synthetic sponge. Natural sponge is kind of expensive compared to the cheapo synthetic and really don’t give you any advantage when it comes to painting stonework.
The Sponge Roller
You will need a piece of sponge, or sponge roller, a small paint tray or similar and some earth tone paints. Apply a pea size blob of base color and add a tablespoon of water to thin it out. Mix up the paint and water into a wash. Watch out for blobs of pigment. You don’t want heavy concentrations of paint on the casting. It’s best to blot the sponge on a piece of paper, or on the backside of the casting first to make sure that this won’t happen.
Once you are happy with the blot test, try applying with a light touch. Pick up the sponge or roller after each pass and reorient the casting to prevent tiling.
Note: You can still individually fine tune the stones, but the majority of the casting’s coloring will be done by these quick application techniques. See the next section.
Don’t be afraid to use a thinned sierra or red oxide at this stage, even if you are creating a gray granite wall. The browns add a tad bit of contrast that breaks the wall up from looking like one color. We call this a sublight because it is not used to highlight, but to break up the coloring of the stone within itself in a subtle way. It is a detail in itself.
Step 3. Fill
The base step is used to establish the overall variations of colors in the wall. This step helps create the look of individual stones. The trick here is not to get too crazy. You want to give the hint of separate stones, not create a checkerboard. Be subtle. You can always add on top if you start out with light colors.
We’ve found that a light brown wash on random individual stones helps give the impression of quartzite rocks.
Granite schist and other metamorphic rock like gneiss along with veining can be created by using a wash with more pigment and some simple brush strokes. Individual sedimentary (sandstone/brownstone) stones can be created by using a light to dark chocolate colored wash
4. Joint darkening (Ink Wash)
Although it’s not necessary for you to use an ink wash on NE Brownstone’s walls due to their deep grout lines, it is recommended because of how well it helps bring out the colors and make the stonework stand out. There is no special formula. We simply place a dot of ink into our mixing tray; add some water (you can use alcohol) and mix it up a bit. We use black drawing ink, but India ink works fine. Beware that some inks will give a bluish tint when thinned.
5. Specific treatment (weathering and natural staining)
This step deals with the final details like weathering and specific staining like rust streaks, mold and efflorescence . The environment that the stones are in has a lot to do with this, so if you model arid regions (western USA) your stonework will be light in color. If you model an area like New England, soot from years of steam locomotives and exhaust from automobiles mixed with rain will give stone a dark gray, streaky appearance.
There’s Fungus among us.
Just like moss grows on the north side of a tree, so it does on a rock. Stone walls near water or moisture will begin to grow moss and lichens, which as shown before will alter the final colors of any rock. Green is often overlooked as a weathering color for stone, but it is quite evident once you know it’s there. We’re not talking about painting the rocks with full strength green, only about light washes to give a hint of mold. Paints like pale or celery green work great. They dry light and give the impression of dry mold.
Streaking. (not the birthday suit variety)
Efflorescence (not effervescence)
Wet Stone is darker than dry Stone
Also notice the wet spots and how they are darker. A darker black/green is perfect for depicting wet or moist mold and is especially useful in and around waterfalls and river scenes.
Chalks and weathering powders
If your wall looks a bit too dark, a light dusting of yellow or burnt sienna will lighten it up and give the wall a dry dusty look. The key here is light dusting. Be Subtle.
• Use light washes
• Use a modified paint roller for fast fill.
• Plaster stonework base coloring should look bone dry. Flat. Add “wet spots” later.
• Light brown wash on random individual stones helps give the impression of quartzite rocks.
• If the stonework is “Dry Stacked” then use Alcohol/Ink (AI) stain after the main colors are employed.
• Wet is dark and dry is lighter in color.
• Mosses and Fungi will grow in and on wet areas and on the north side.
• Wet slimy moss is a dark Green/Black (good for streams and waterfalls)
• Dry moss is a lighter brown or pale green
• Some stones can have a totally different color due to lichens and other moldy stuff growing on them.
• Don’t be afraid to add gray. Use stippling with light grays to create lichen growing on rocks
A medium sized round (flame tip) brush works great for applying washes to individual stones and for ink washes. You can get these in a variety pack from most craft stores.
Foam roller You can get these at any home improvement center and will last you lifetime if you take care of them and if you don’t want to sit and pick out foam to create your own texture you can purchase pre-textured here.
A lid from a margarine bowl can be used as a mixing palette for the washes.
Nitrile gloves to keep paint from staining your hands and fingers. Nitrile has pretty much taken over the latex glove market since people can have allergic reactions to latex. Nitrile, not so much.
A can of flat clear polyurethane spray for sealing. You can get this at any home improvement center and it does not have to be the particular brand I link to above. It only has to be clear with a flat finish. It should also be used on top of your stonework once it is painted to help prevent unintentional paint removal.
A roll of Paper towels helps. Nothing special here. Just your typical roll of paper towels. You can’t have enough of these.
Distilled water is recommended. You don’t have to use it, but we do.