Painting Matters #5: Paint Handling I
by Judith Northwood
Remember, your question can be answered here! Just post a response or send me an email with any of your painting quandaries or frustrations, and I’ll select from those for future columns. This week’s question is from comments made about my first column on selecting a brush.
Q: How thick or thin should paint be when painting a miniature?
A: That sounds like a straight-forward question, but the answer honestly is: “It depends…”
All acrylic paint lines I’ve ever used have needed to be thinned at least a little for every technique I’ve tried, but the consistency desired depends on the technique and the step within the technique, and the amount of water and/or medium to add depends on which paint line you’re using and sometimes which paint within a given line.
Let’s start with layering. Some painters work dark to light, some light to dark. Myself, I like starting with the mid-tone and working down to shadow then up to highlight. I find it easier to do layering when I think of the process as modifying that central color, but I know these sorts of preferences are highly personal. I recommend trying all three approaches to layering to find out which feels the most natural to you.
If you’re working dark to light, I would imagine that you probably use a black primer. The column before this one (Common Color Challenges I) has some suggestions for avoiding dullness with an intermediate-colored layer between the black primer and a bright color of paint. In any case, though, you’ll want your first layer of color to be thin enough to flow off the brush, but not so thin that it will take a dozen layers to establish the color over the black primer. Transparency isn’t your friend for this layer, but a flow enhancer product is, especially one of the fine art brands that you mix one part of flow enhancer to ten parts of water. Using that mix instead of water alone will reduce the water’s surface tension and enhance leveling in the paint, making it easier to achieve a smooth, even coat for your first layer and to apply slightly thicker paint without the paint holding brush stroke marks. Ideal consistency would be similar to heavy cream or buttermilk for most paints.
There’ll be a sense of body to the paint, not entirely unlike dessert gelatin when it’s just starting to set. If you put a drop on a paper plate then tilt the surface, the paint should run slowly, leaving a distinct and relatively even trail behind. For most hobby paint lines that I’ve used, this was somewhere around three parts of water (or water/flow enhancer mix) to one part of paint, but that’s most definitely not a hard-and-fast rule. When you dip just the tip of your brush in the paint, you should be able to see the paint flowing up into the brush, and if you try to scoop paint up with the brush, there shouldn’t be a noticeable dollop that retains its shape sitting on the brush. For paints made from pigments that tend to be more opaque than transparent, two layers should be the most it will take to get decent coverage. If the pigment tends to be more transparent, you may need to add a little more paint, making the mix thicker; in which case, the flow enhancer becomes very important in keeping a smooth layer of paint. To avoid frustration, this is one step where I strongly prefer a vinyl-based acrylic paint, since that particular acrylic binder promotes opacity and coverage.
Later layers should be more transparent and anywhere from two to five times as thin, depending on the pigment-load in a given brand of paint, so a consistency from whole to skim milk (yes, there’s quite a difference between the two). The more pigment, the more the paint will need to be thinned. This is where nothing I can say will serve you better than experimentation with the paints you have. A lot depends on the working properties of the brand of paint. You can stay a little thicker and have more control if you add a glazing medium and some matting agent or add a fluid matte medium, since the mediums will increase transparency without thinning the consistency as much. Most fine art brand glazing mediums are high gloss, but Vallejo Model Color has a matte glazing medium, and many lines have a fluid matte medium. By and large, you can successfully thin a great deal more with dark colors than pale, and paints designed for animation cells tend to be the most successful in extreme thinning without losing coverage or control.
What you want is paint that stays where you put it instead of going everywhere on the mini, but is transparent enough that the edge where the layer stops isn’t obvious. Using the paper plate technique again, a drop of paint thinned for later layers will run fairly quickly, but will still leave a distinct trace, although lighter and possibly with some skips or a little bit of beading. If you can’t see a trace, it’s too thin, and if there are more beads than line to the trace, you definitely need some flow enhancer, because the surface tension that causes the beading will make it harder to achieve a smooth, flat layer.
If you’re going to do a wash over an area to tie all the layers together, thin that layer about to the consistency of tea. A bit of fluid matte medium is a good idea, because adding water reduces the amount of binder per ounce/ml of paint; thus, thinning makes the paint film progressively more fragile with the amount of water added. Extreme thinning means extremely fragile, easy-to-damage paint. I’ve thinned paint enough, on occasion, that my next layer lifted the previous one right off the mini.
As a general caveat, layering, like any kind of wash or glaze, works best when you don’t apply too much paint at a time. More problems come from overloading the brush than from exactly how much the paint is thinned. You don’t want the paint to pool, which can often cause darker rings and blotches as the paint dries, nor do you want there to be brush marks or gobs of paint on the first, thicker layer. After loading your brush, touch it against a damp paper towel or the back of your hand. This will remove excess, but still leave plenty of paint on a good brush to cover quite a bit of a miniature’s surface. If you notice a pool of paint on the mini, quickly pick up a clean, dry brush and use it to wick up the pooled paint, then go over the area again with a more lightly-loaded brush. For a ridge or gob, use a clean, damp brush and gently smooth it out.
The other fundamental technique where consistency can matter a lot is wet-blending. Overall, layering works best with paints that differ in value (dark to light) but are all close to the same hue, like all red-brown or all blue-green. Wet-blending, on the other hand, can allow a smooth transition between clashing colors, like turquoise to scarlet. Wet-blending works best when the two paints you’re using are thinned to a similar consistency, and the effect comes together the fastest when you’ve already laid down a layer of each color that just barely touch, let that dry completely, then do the wet blending on top of that.
For general use, where you want the two colors each to cover fairly completely, aim for the heavy cream or buttermilk consistency that I described above. You can achieve some interesting effects, though, by wet-blending your shadows or highlights on top of a mid-tone layer. In that case, you’d want the paint to be thinner and more transparent, more like the milk consistency discussed above.
Wet-blending requires what fine artists call open time, a period of time in which the paint remains wet on the painting surface. To gain open time with acrylic paint, you usually have to add drying retarder, especially when the consistency miniature painters most often use requires that a fair amount of water be added to the paint. Generally, the more water, the faster the paint dries, which is great for layering, but not so ideal for wet-blending. With a bit of retarder mixed in instead of just water, you’ll have more time to work with the paint on the surface of the miniature and achieve a smooth blend. Retarder, however, is typically clear, and will enhance transparency on its own. To be sure you’re getting the effects you want, add retarder before adding water, or you might end up with paint that has less coverage than you’d intended. When you’ve used retarder, always let that area dry completely before attempting to add more paint above it.
I’ve mentioned a bit about how the whole process of thinning varies among paint lines and even among colors in a given line. Each brand tends to use different amounts of various additives that effect the working properties of the paint. Some brands have more flow enhancer than others, and so will need less water to achieve the same working properties as another brand. The key is to experiment with the brand that has the colors you like until you get the feel for how much thinning it requires to achieve the effects you want. It’s also not impossible for different colors of paint to require different amounts of thinning to reach the same degree of transparency simply because of the differences that exist among pigments. A blue paint made with a phthalo blue pigment will be a lot more transparent than one made from manganese blue or ultramarine blue pigments.
In general, fine art lines will tend to be more transparent than paint lines intended for graphic, animation or decorative artists and those made specifically for the miniature painting hobby. Vinyl-based acrylics will be more opaque than paint made from other types of acrylic resins. Matte acrylics are more opaque than glossy. Acrylic gouache and ink, soft-body, fluid and airbrush acrylics will have more flow enhancer than heavy-body acrylics, since heavy-body acrylics are designed to retain brush stroke marks, and the others are all designed to smooth themselves out, acrylic inks and airbrush acrylics the most. Fine art lines will tend to have a higher pigment load than those made for decorative artists and the miniature painting hobby, allowing greater thinning without losing the color entirely.
Metallics work better when they’re not thinned a great deal, since the smooth metallic effect breaks down to a glittery sparkle when there’s too much space between each of the tiny chips of mica that give the reflective quality to make the paint ‘metallic’ in appearance. Try metallic inks with some matte medium if you prefer working with thinner paint, as they’re designed to have greater fluidity without losing a smooth result.
I’d like to be able to give you crisp, clear directions for exactly how much paint should be thinned or what consistency will work the best, but there’s way too much variety in the paints and mediums available to us for any one set of directions to work the same way every time. Experimentation is the best way to know what works best for the paint you have, and also for your personal style, so I’ll repeat a frequently-given piece of advice: Get some inexpensive watercolor paper, spray it with your primer of choice, and try some techniques and consistencies of paint on those swatches. It’s natural to get caught up in wanting a mini to turn out just as you wanted it, but that feeling promotes sticking to what’s familiar rather than encouraging freedom to try a variety of consistencies of paint, mediums and techniques. It’s also worlds less discouraging to toss out a swatch that turned out badly than it is to struggle with a mini that isn’t going so well. It may seem like a distraction from getting those minis done, but you’ll find that the practice makes the painting more fun and a lot faster.