Painting and Weathering Rocks

In last week’s post I shared with you some of the work I have been doing on my new N Scale modules for the Solent Subdivision.  I focused on using homemade rocks to form a river canyon; you can find the post here.  In this week’s post I’m going to share with you a fast and simple way to color and weather your rocks.

The first thing you need to do is get some reference material to help work out what colors your rocks are going to be.  A simple internet search for river canyon or railroad canyon will bring up all sorts of results.  For example here is a link to an image of a river canyon with similar colors to mine.  Typically base colors for rocks will be gray, brown, yellow or red.  This will depend on the geology in the area you are modeling but mostly it will depend on what you want it to look like.

Once you have decided on your color palette you can pick the paints or stains that you will use.  My rock faces will be based on brown and yellow.  Again I have turned to Woodland Scenics but there are plenty of suppliers of scenic paints or you could simply use cheap acrylic paints from a hobby store.  I am using Burnt Umber and Yellow Ocher as my base colors. Raw Umber is another good base color which will give a grayer finish.

Colouring Rocks 3

If you wanted to add a bit more red into the color palette Raw Sienna is a good choice but be careful as a little goes a long way and you don’t want to overdo it unless you want a strong red all over.

Because the cast plaster rocks and plaster cloth used to join them all together are porous it is better to stain them using a pigment rather than paint them.  This is because the pigment will be soaked up into the plaster and the colors will bleed into each other giving a cohesive look to the color.  Simple paints on their own would give a blotchy look because the color will stay in the area applied under the brush. The colors from Woodland Scenics are called pigments and are designed to be diluted with water; acrylic paints can be used in the same way.  The other main color I will be using is black and for this I have a simple black acrylic poster paint.

Using three separate plastic pots, one for each color, I prepare the pigments.  In the image below you can see I have added just a little Burnt Umber into the bottom of the pot.

Colouring Rocks 1

Then I have added water to dilute the pigment.  The bottle says to make the mix 1 part pigment to 16 parts water.  I tend to use a little less water with the lighter colors but it is all down to personal taste and you can also get different effects by changing the mix as you go. The main thing is to make sure the water and pigment are all mixed together.

Colouring Rocks 2

Using an old paint brush or sponge brush, or just a piece of sponge will do, start by dabbing spots of the diluted pigment onto the rocks in a random order.  The technique is called leopard spotting.  You will notice the plaster will instantly soak up the water from the pigment and the color will bleed away from the spot you touched with the brush or sponge.  I started with the Yellow Ocher as this will be my least dominant color.

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Then with the next color, Burnt Umber, I filled in the areas around the Yellow Ocher.  When doing this if you think there is not enough Yellow Ocher you can simply go back and add some more.  The main thing is to ensure all the white is covered.  Depending on the type of rocks you are modeling and your color palette you may also be adding in a third color such as Raw Sienna.

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Although the rocks are starting to look nice a lot of the details are still looking flat; that is to say the detail in the cracks  and crags are not showing as well as they could do.  Also the the rocks are looking very clean which is not very realistic.  To solve this I use my final color which is the black.  Again I have diluted the paint with water but this time I have done it roughly 1 part paint to 32 parts water.  I say roughly because whenever I do this I always try a little first then add more paint or water until I get it the way I want it.  Diluting it so much will make it into a wash rather than a paint and this is what we need to bring out the detail without eradicating the previous colors.  The wash is also applied with a brush or sponge and will run down into the cracks and crags a little before the plaster has a chance to soak it up.

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You can apply more or less of the wash depending on the finished look you are after.  If you think you have added too much and the rocks are now too dark you can simply add more of the other diluted pigments over the top.

Colouring Rocks 8

It is a good idea to keep stepping back as you work through the process because it can look different when you are not so close.

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On the other side of my canyon you can see all three stages from left to right.  When doing large areas of rock in stages it is a good idea to stagger the finish line, this will make it easier to blend everything together.

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Stepping back again you can start to see how the colors will work together.

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And finally here is a shot with all the rocks painted.  The green is simply an undercoat in the areas where there will be grasses and vegetation but you can see how the overall effect will look.

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Although the main rocks are finished the canyon is not.  I still need to add in lots of detail such as fallen rock, known as talus or scree, as well as all the vegetation before finally adding the water.  And I believe there is a small matter of a railroad trestle.