Before the oils I tend to apply a filter. A filter is a very, very thin wash over the entire surface; its job is to bring all the colours together and get a nice grimy finish. For this model I used AK Interactive Winter Streaking Grime which is a grey green tone which works well. Sorry for the lack of photos, when my battery is getting low it doesn’t save the images. Here is an image from a Gecko I made a few months ago.
The first stage of the weathering is working with oil paints. I prefer weathering with oils as I find the blended effects are very realistic and much easier to control than say using pre-shading. My favourite oil paints I like to use are from Abteilung, they seem to contain less linseed oil which makes them faster drying and more matt in appearance although sometimes I will mist on some matt varnish on occasion. Usually I won’t bother though and the oils leave the surface with a nice realistic smooth metal effect.
I tend to put a small blob of the oil paint onto a piece of scrap card, this will draw out the linseed oil making them dry even faster and be more matt. I say even faster but it will still be a day or two before you can use thinners over the top with confidence hence sometimes I will mist over some acrylic matt.
You will need a selection of brushes, some white spirit (in this case AK Interactive) and some kitchen roll to wipe the brushes on.
The first stage is to dampen the surface with white spirit, this is important on a matt finish otherwise the oil paint can stain the surface which is not what we want.
Next we take a small brush and place tiny dots of the oil paint onto the surface. First up I like to do the fading effect so white, buff and yellow are used. Yellow over a green base is nice because it makes the colour warmer, white alone can result in a chalky finish. Bright green is also useful in creating chromatic richness.
Taking a damp (ever so slightly damp) flat brush we slowly work the oils into the surface. Try not to mix the paint as otherwise we’ll get a filter effect; we just want it very localised in order to get a gently marbled finish.
To finish we take a large soft dry brush and finish off the blending.