This is a Guest Post by misterjustin
The question I've been asked the most since I started posting this semi-regular series has been, "how did you achieve that realistic rock look on your Runic Mountain bases?"
And so here it is - my method for painting realistic rock using Winsor & Newton Artesian Oils. This is a line of water mixable oils made with a modified linseed oil. You can pick them up at most art shops - including Michael's in the USA - and the basic starter set will likely last the life of your hobby.
In the demonstration I'm using Phtalo Green, Raw Umber and Payne's Gray. For a lighter look, such as the finished image at the top, I add Raw Sienna. For a darker look add some Lamp Black.
With water mixable oils there's no need for astringent cleaners; soap and water work just fine. The drying time is considerably less than traditional oils, maybe 1-2 hours, and you won't want to paint over the oils until they're completely dry. You can test this by rubbing your finger gently over the oils. As with anything that's going to be handled, a clear sealant is recommended.
Start by priming the model or base. The color you use at this point will eventually show through in spots so think ahead. I recommend white but have split this base for effect.
Realism is achieved by using a technique similar to the dot filter method with oils. In this case we're going to use more paint and wash less of it away since we want to keep more of the color. Simply get a bit of oil on the end of a brush and apply dots to the surface.
Using a slightly damp brush alternate dragging and stippling the colours to create an uneven mix. Blending away from the raised areas will create a natural looking shadow in the recesses. At this point it doesn't look like much but...
Using a clean, dry paper-towel or tissue very gently begin wiping away the paint. Wipe with the flow of the rock formation - that is from the base to the top - and you'll leave more paint in the recesses.
By wiping paint away selectively you can achieve a very natural, realistic rock effect with very little effort. I managed this base in just a couple of minutes while waiting on a pressure tank to cycle. Once this is fully dry the effect is much more realistic.
Try different colours for different effects and vary how much of the paint you remove. On the Runic Mountain bases product image I used a lot of paint and removed very little. On the demonstration I skipped the Raw Sienna and wiped off most of the paint so that the effect was more visible.
If you have a question about basing, weathering or other detailing please leave it in the comments or email misterjustin at secret weapon miniatures dot com. I'm more than happy to explain any of the tips and tricks I use.