When I first started miniature painting, there were two techniques that seemed like elite level god tier things that are the difference between someone who is okay at miniature painting and a true master. One is non-metallic metal, and the other is Object Source Lighting, or OSL. I think it is telling that both of these are about doing tricky things with light, but I digress.
OSL in particular sounds a over the top. Basically, it is painting the miniature such that if you have a glowing part of the model like a lightstaber or a glowing sword, you paint the glow of the light onto other areas of the model. For example, if you’re painting Darth Vader, in order to sell the glow of the lightsaber, you may want to place some red glow onto his cape where the light from the lightsaber is hitting and reflecting off his black cape.
Now, before we get too deep into it, let’s discuss some of the theory behind this to avoid some common mistakes. First, and let us just get out of the way first, this is the sort of technique where realism takes a back seat to artistic license. For something to really light up a model in the way we commonly do with OSL and bathe it in coloured light, it needs to be almost unrealistically bright. Which, I suppose isn’t a big deal when we’re talking about glowing swords and lightsabers, but it is something to keep in mind. We’re trying to sell an effect, not necessarily be super realistic here.
Secondly, we need to think about the ambient lighting as well. In bright sunlight, any light emanating from a glowing thing is going to be overwhelmed by the ambient light of the sun. However, if we’re on a moonless night, then the object in question is going to be the only source of light and we’re going to have strong OSL. Consider, for example, the below pictures of Aayla Secura and Darth Vader. Aayla is outside in daylight, so there is little to no OSL, while Darth Vader is in the dark and we can see the glow on his cape and hand.
We also need to think of the relative strength of the source of the light, the glow, and the rest of the model. When you’re doing OSL, the brightest spot should always be the source of the light. For coloured light, this could almost go to white. Next should be the glow, then finally, the rest of the model not basked in the glow of your glowing object. This means that you need to make sure you have somewhere to go in your colour scheme. OSL works really well on dark colour schemes like Darth Vader; for white models like Retribution warjacks, it can be tricky to get the glow brighter than the rest of the model because you’re trying to make something that is brighter than white. Which is hard.
Finally, light tends to emit from objects in a straight line. It can diffuse a little around corners, but when you’re placing your glow effect, you need to be careful that the places that are shadowed from the light emanating from your glowing object are in shadow.
Now, if only we had some sort of device that can shoot paint out from a point and in a straight line…
Ruin and Airbrush OSL
Getting back to this model for a little bit, Ruin is the product of a bunch of Khador experimentation with ancient Orgoth relics, so it is a warjack powered by a mixture of coal and the souls of the dead. While the default sculpt is pretty cool, I decided I wanted to kick mine up a notch by adding a glowing patch of swirling souls to the right shoulder, as well as a some poor Cygnar long gunner on the base and a wisp representing his soul being sucked out of his body and into the shield.
With the model painted and weathered in largely the same scheme as my Grolar and the rest of my army, and after dropping it off my desk and having to pin it back together, it was time to hit it with the OSL. As this is a robit chock-full of evil magic, I wanted to put in a lot of glow effects. The sculpt had a number of runes carved into it, which I wanted to make glowing, as well as the shield, soul, shoulder, and visor.
For the soul and the shoulder, I did paint them beforehand, trying out GW’s new ghost technical paint, the Hexwraith Flame, over a near-white base. It kind of worked, though you do need to highlight this to get the proper effect, either with layering or dry brushing. However, for the runes, all I did was drop some white paint into the rune as an undercoat.
From there, we’re going to mix up a glaze in our glow colour and drop it into an airbrush, thinning it enough to increase the transparency. The only challenge here is trigger control; you may want to practice on something else first, but you want to be able to pull back just enough to barely tint the target. Once you start seeing the colour starting to change, you can simply stay on target until it you get the effect you want. Finally, it is worth experimenting with both inks and paints until you get the colour and consistency that works for you.
For things like the runes and the visor, simply point and shoot. The paint hitting the . Since we’ve undercoated the source of the light with white, we will naturally get the effect we want — brightest at the source of the light, and duller in the areas of the glow.
When it comes to larger objects like the wisp of souls, what we can do is use the fact that an airbrush shoots paint in a straight line emanating from a point to our advantage. Simply fire at such an angle as though the paint is coming out roughly from the light source and hitting the model. This will lay the glow in where it would naturally fall.
And that’s about it. You may need to go back and reinforce some of the light sources with a little white, or play around with some washes overtop, but a few simple airbrush tricks can get you a passable OSL in no time at all that makes you look to the untrained eye like an elite god-tier painter.