Weathering with art supplies part 1: oil paints

Oil paints are easily the most versatile tool I have for weathering models. There is almost nothing that can't be done with them; Mike Rinaldi says so! Textured dirt/mud is about the only thing I can think of that oil paints can't do.

Oil paints have a simple list of ingredients: 1) drying oil; 2) pigment. A drying oil is an oil that does not evaporate, but solidifies to a solid film through oxidation. Examples are linseed oil, safflower oil, poppy oil, and others. Linseed oil is the most widely used in oil paints. But always check the label on the tube to see what you are getting. Higher quality oil paints may use a mixture of linseed and safflower oils. White oil paint is also often made with only safflower oil because it does not have a tendency to yellow over time. Again, check the label.

I have some oil paints from AK Interactive and 502 Abteilung, but I mostly use Winton paints by Winsor & Newton. The Winton paints have a slightly smoother consistency than the modeling oils, but I don't know if that is due to a different oil, a different process, or a different ratio of oil to pigment (the modeling companies are not so generous as to share any information regarding the content of their paints). Other than the different consistency, I don't notice any difference between the modeling oils and the artist oils.

Materials and Tools

These are the materials and tools I use for weathering scale models.

paint--I use mostly Winsor & Newton's Winton oil paints. They are not the most expensive oil paints, but they aren't the cheapest. I have been told by artists that these paints and better than cheap oil paints for a variety of reasons, mostly because they have very finely ground pigments. I haven't used any other type of artist oil paint so I can't really compare.

I buy my oil paints individually, rather than in sets. Different brands may have a different range of colors or different names for the same color. I have about 15 different colors, but I don't use them all. If you want to get started with artist oils, the following list is a good place to start:

  • burnt umber--dark reddish brown
  • raw umber or Van Dyke brown--dark brown like above, but less reddish
  • burnt sienna--good rust tone
  • green--I have 'sap green', but 'oxide of chromium' is probably a better military green
  • payne's gray--pretty close match to Tamiya's German Grey. It's a very cool, bluish gray
  • naples yellow--a light desert sand. When mixed with burnt umber and white, it makes great dirt colors
  • white--zinc white or a mixing white, or titanium white
  • ivory black

Artist colors are typically vibrant, so it is helpful to mix colors to tone down the vibrancy. I have a book of color mixing recipes that is helpful (see picture).

thinner--When necessary, I thin the oil paints with Mona Lisa brand Odorless Paint Thinner. I find this brand doesn't adversely affect the acrylic paints I use, while also providing adequate dissolving power. The odorless spirits don't dissolve the paint as well as the regular mineral spirits, but I find it perfectly adequate. The bonus is that I don't suffer from day-long headaches that come with the odor. Mind you, odorless spirits aren't any safer than regular spirits, they just don't smell.

brushes--I don't use expensive brushes for weathering; the techniques I use are not generally kind to the bristles. I use cheap artist brushes for that reason. Don't go so cheap as to get the ones whose bristles fall out, go a step up from those. I use round brushes from size 20/0 to 5 and flat brushes from size 2 to 4. But feel free to use any brush size or shape you are comfortable using.

palette--I use a disposable paper palette. It saves on clean up and won't absorb liquids.

kneaded eraser--a pliable putty-like eraser that I use to pick up excess oil paint from the model.

drying poppy oil--a medium that I mix with the oil paints to add transparency.

Surface Preparation

I paint my models almost exclusively with flat, acrylic paint prior to weathering. Whether to apply a gloss or satin coat before weathering is strictly a matter of personal preference. I prefer to apply my oil paints to a flat finish, including washes. Anyone who advises "never" to apply a wash over a flat finish has simply never tried it (nor have they read Mike Rinaldi's Tank Art books). They are just blindly repeating the (often bad) advice they have read. This may be the biggest myth in scale modeling. I'm not saying that you can't or shouldn't use a gloss finish. I'm just saying using a flat finish is a legitimate option. Feel free to stick with a gloss finish if that is what you prefer, but stop saying "never"!

Because I use fast-drying acrylics, I sometimes find that the painted surface is slightly rough or pebbly. When this happens I find it necessary to sand the paint with 2000 grit 3M wet/dry sandpaper. If I don't do this, the oil paint will settle down in between the tiny bumps, causing tiny spots of the base color to show through the oil. This is not the affect I want (usually).

Paint Preparation

Almost every article I read suggests that modelers put the oil paint on a piece of cardboard to draw the oil out of the paint. The stated purpose of this is to make the paint less glossy. After trying this and testing this myself, I find that this has no effect on the amount of gloss or sheen. Furthermore, I prefer the consistency of fresh paint. Finally, removing the oil will make the paint more opaque, which is usually the opposite of the effect I am trying to create. Perhaps I will detail the testing in another post, but for now, I will just say that I prefer to not draw the oil out of the paint. Feel free to experiment yourself and stick to your own preferences.

Be aware that when I use oil paints for filters and washes, I thin them--lots. There is no paint in the world that can be thinned with 90 to 95% thinner and remain stable; the solids will settle very quickly. Therefore, it is necessary to stir the paint frequently. I stir with a paint brush, mostly because toothpicks don't work when the paint is this thin.

Filters

A filter is an extremely thin coat of paint applied to a large area or an entire model. The purpose of the filter is to slightly alter the perceived color like a filter on a camera. The usual advice to mix your own filters is to use a ratio of 5% paint to 95% thinner. However, it is difficult to measure the volume of oil paints because of their high viscosity. So here is what I do to mix a filter.

  1. I put a small amount of odorless thinner on my mixing tray (I use a plastic one that has round indentations (see picture)). Note that I don't mix up an entire bottle of paint--I mix only what I need.
  2. Using a round brush (size 0), grab a blob of paint with the tip and stir it into the thinner. I'll pull the paint straight from the tube or from a palette if I mix my own color. Doing this once will give me an extremely subtle filter; for a less subtle filter, I'll mix in another blob of paint.

The above picture shows a filter made with two blobs of burnt sienna (click to enlarge). The smudge on the palette should give you a good idea of how thin this paint really is. I like to use multiple very subtle filters rather than a single harsh filter. I find it easier to add more filters than to try to partially remove one that is overdone.

When I brush the filter on the model, I don't flood the model with paint. Using a flat brush, I apply just enough to create a damp layer rather than create pools of paint. This requires that after I load the paint brush, I touch the brush to the side of the plastic tray to remove about half the paint. After I apply the first filter, I blow it dry with a hair dryer. When it no longer appears wet, I can assess the effect and apply more filters if necessary.

The image below depicts a sequence of three filters of burnt sienna applied to the back of a toy Sherman turret. Please ignore the giant seam; it is a toy after all.

 

As you can see, the first filter is barely noticeable. Sometimes only one is enough if I am going for extreme subtlety. Two filters are more noticeable, but still subtle. Three filters are now quite obvious. Remember this filter was made with two blobs of paint. When using a filter with only one blob, I may need to apply a dozen filters before I get the effect I want. But that's the amount of control I like to have. It's up to you to determine how many you wish to apply.

Washes

I prefer the pinpoint type of wash rather than the "all over" wash. That is, I apply the wash only to the recesses and nooks and not the entire surface of the model. The procedure for mixing the wash is the same as the filter, only I use twice the amount of paint--about 4 blobs for the same amount of thinner. To apply the pin wash, I take a 10/0 or 20/0 round brush and just touch it to a recess or detail. Capillary action will draw the paint along the recess or detail. If the paint gets to a place I don't want it to, I can lift if off with a kneaded eraser or brush it off with a clean brush and a small amount of thinner. For those of you who do not believe that you can apply a wash over a flat finish, the picture below proves you wrong.

That's it for this part. In the next part I'll show you how I do streaking, fading, and more with oil paints.

Previous article: Weathering with art supplies: Introduction

Next article: Part Two