How to Paint a Gundam with Brushes
Martin's Introduction
While in Taiwan I had the good fortune of ready access to spray paints, since setting up this little site and receiving letters from other modelers, it's become apparent that good modeling spray cans aren't available in many areas. (Indeed, at the time of this writing I'd recently discovered that my favorite Gundam Color spray paints aren't internationally available at all outside Japan, Taiwan, and perhaps other nearby Asian countries.) Many of my readers instead chose to paint their models by brush.

While my modeling career began with some brush-painted miniatures years ago, painting Gundam models by brush is hardly my specialty, as my early effort to paint my HG 1/100 Tallgeese by hand clearly demonstrated. However, my friend and fellow Gundam modeler in Italy, Alberto, became quite a proficient brush-painter in his quest to paint his Gunpla collection despite lacking spray paints. Wishing to provide my readers with useful information should they seek to paint their Gunpla by hand, I asked him to prepare a guide to that end. He has helpfully obliged by providing the following advice, complete with his own photographs.

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When Martin asked me to write these lines, I felt somehow proud of myself.

I wasn't used to painting my Gunpla and other models fully. I only used to cover over clip marks, or paint where a color needed a complete change. Just think that my HG Gundam Wing models were molded in grey instead of white, and I left them like that only because I thought I would never have been able to paint them well. But, after visiting this site, I admitted Martin was totally right, and I realized for the first time that my little Gunpla collection needed and deserved a coat of fresh paint.

Anyway I wasn't in the mood to buy an airbrush, which was too expensive for me, and spray cans suitable for Gunpla aren't easily available here in Italy, so I decided that old brushes were to be used. I admit I was influenced in making this choice by my mother, whose hobby is pottery painting. She helped me a lot in learning the technique to get gradations with two wet colors (see below), and, above all, to make friends with the odd objects which brushes and color bottles may seem to be.

So, little by little and following Martin's guide and my mother's hints, I succeeded in what I wanted. My results are now good but not comparable to Martin's inasmuch as brushes will never compare to a good spray can in painting a Gunpla's basic colors. Brushes are, instead, essential in some techniques I'll speak about later. I got this valuable experience in Gunpla brush-painting, and I'm glad I can help Martin in his task. It will be my way to thank him for all the hints he gave me with his little guide on the Net, and with the many emails he patiently sent me every time I happened to show him my works.

Figure 1: Some of my old school tools.

So, let me ask at once the main question these paragraphs are supposed to answer: can a Gunpla modeler use old brushes instead of a modern airbrush or spray cans to paint his models?

First Considerations on Colors and How to Hold Pieces

Fig. 2: My Brushes are Old, but Still Working.

The answer is of course yes, he can. Yet I must say I can't find a reason why anyone who can avail himself of an airbrush or spray can shouldn't use it to paint his models, and prefer to use a normal brush when his aim is just to have a flat-colored model, without hues, gradations, or weathering (which can be obtained instead with a brush, and sometimes only by using a brush).

One might have many reasons not to buy an airbrush or cans (they're expensive, or you don't want to buy them only to paint a small number of models, or in your country spray cans aren't sold), but I think you must use them if you've got the opportunity, because they really provide better results incomparable with those you could get with a simple brush. Of course, this is in regard to getting the first flat layer of your main color.

If you haven't got the opportunity to use an airbrush or cans, you will nevertheless get good results with a normal brush, but some peculiarities of this technique must be pointed out in order to solve the most common problems you may find in painting your Gunpla with brushes only.

First let me explain a bit about acrylic (that is, water soluble) color composition, as this will always have to be kept in mind while painting with brushes.

Colors, usually sold in small bottles, are made with a tinted part, the pigment, and with another part which lets the pigment stick to the painted surface after drying, called the binder. In some colors, which look very liquid when you buy them, pigment and binder tend to separate after a while, and you need to stir the color very well before using it. (Toothpicks can be used to mix your paint, as well as brushes.) Otherwise you'll get too much binder on your brush, with the result of no color painted on your model. Sometimes pigment becomes visibly too dense and hard, almost floating in the liquid binder. In this case, adding some drops of thinner will solve the problem. This trouble is quite common with Tamiya colors, which in my opinion are designed to work with airbrushes more than with normal brushes.

Fig. 3: Very Liquid Tamiya X1 Gloss White. A Patina of Binder Covers All the Pigment.

Other colors look denser at first sight, but they don't tend to separate inside the bottle. For example Games Workshop colors don't need much stirring, but they dry much more quickly than Tamiya colors. You must be very careful to close the bottle very tightly, so as not to let even a little air enter and dry your color before you use it.

Fig. 4: Much Denser Games Workshop Bloody Red

Non-acrylic colors are also available, but I've never used them, so this tutorial will be limited to painting Gundam models with acrylic colors.

Many people use masking tape to get some kind of contour. I do this too, but not very often, as brushes always leave a little more color around tape. A tiny color line may therefore form after removing the tape.

Let me make here another litter general consideration. About how to let pieces dry, there's nothing to add to what Martin has already explained. About holding pieces while painting, of course you can do it with pliers, but your hand will often be enough. Just hold the piece by using an inside pin. If no pins are available, find a side to hold it and paint all other parts, being careful to arrive as near as you can to the rim of the temporarily unpainted area. Let the paint dry and later paint the remaining area, being aware that the rim might give you some troubles (to be discussed below). If your piece is enclosed (like a sleeve of armor for a leg or arm) you can also put a finger inside the piece to hold it. If the piece is sort of a ring (like RX-78-2's yellow neck armor), a toothpick pinned in a cork can be a good base to paint the piece and let it dry.

Fig. 5: Cork and Toothpick Array Used to Suspend Drying Part

Thinning Out and Spreading Paint
The first problem you'll find when you use a brush is thinning out the paint (also called 'watering down'), that is making it more liquid by adding water to your dish, tile, or whatever you use as a palette. How much water must be added to get the correct water to pigment to binder ratio?

The answer isn't easily given. Obviously the first thing you must take care of is how much you paint is dense or liquid when you first take it out of the bottle with your brush. A fluid paint needs less water to achieve the right viscosity, but a little water must always be added, as it will let pigment and binder mix better. I happened, in fact, to take a little Tamiya white X1 and stir it without water on a dish. The binder immediately formed a film over the pigment, and I couldn't use the paint at all.

At this point there's another thing you must never forget when using brushes: every stroke you leave on Gunpla plastic behaves like a big drop of color you're spreading on the part with your brush. Airbrushes and spray cans instead spray on the parts many tiny drops, which later join and dry to form a film.

In other words, with your brush you leave this big paint drop on the part, then you try to enlarge the spot you've created by spreading the paint around. As the paint immediately starts drying and forming a film, after a while you won't be able to spread it any more. As the rims of the enlarged drops are the first part that dries, if you're not quick enough to spread the color out, you risk leaving on your pieces an undesirable, strongly-colored rim with an almost transparent layer of paint within.

This is why you've got to use a brush proportioned to the dimensions of the piece. Too small a brush will leave little drops you'll never be able to spread quickly enough, and you'll end up with a mess of paint rim circles.

Fig. 6: Paint Rim Circles and Holes on a Gundam Foot.

Besides, you mustn't forget that your paint drop is also subject to the law of gravity. It sounds funny, but it is an important point to keep in mind: your paint, above all when it is liquid, runs easily along sides and grooves (even if you've sprayed or painted a layer of primer on the piece), and eventually makes a sort of bubble or spot when the binder starts to dry into a film.

Fig. 7: Gravity Has Driven White Paint on the Anklet Toward the Lower Rim, Forming a More Intense Spot.

If you happen to touch this bubble with your brush, the paint will spread, but the rims, which have already dried, will leave a quite visible color line and form a hole in the paint coat. If you don't touch it, the bubble will dry where it is and even if its volume decreases, it will form an unpleasant paint bump on the model.

Avoiding these bubbles is quite difficult, above all with very liquid paints, as Tamiya are. A good way could be moving the piece gently and slowly and rotating it so that the bubble runs slowly towards the opposite side, but when the external film forms, the bubble stops and dries where it is. Finding a paint that dries totally in a very short time usually avoids this problem, provided the paint bubble hasn’t already formed. Otherwise the bubble will be immediately created, and the results will be even worse.

Using a denser paint of course avoids running and spreading because of gravity, but it may cause a different problem: brush grooves on the piece. A brush is, in fact, made with a good deal of hairs (natural or artificial) which might leave a groove in the middle of the dense paint drop, and create an uneven and rough surface on the piece. This roughness of the paint is not visible from far away, but unfortunately everybody notices it on close investigation.

Remember that a paint bubble or a paint hole can be ultimately eliminated only by removing the paint from the part, so, when a bubble is born, you must sand it down with sandpaper and paint again. This sanding must be done when the coat is totally dry, otherwise little fragments of sandpaper will be trapped in fresh paint, and your model will be spoiled. I suggest also washing sanded parts, so that you’re sure to remove all sandpaper fragments. Of course this sanding can’t be done too near panel lines, or they will be destroyed. If bubbles or holes are too many or big, well, take a little solvent and remove  the entire coat carefully. Taking a little more time, even if it could make you angry, is always better than having a Gunpla spoiled by paint bubbles. Remember, anyway, that softer plastic parts are melted by acetone and other solvents, so you have to be very careful in choosing your solvent. Paint holes could be hidden by another layer of paint inside of them when their rim is very thin and not too tall, but otherwise there’s no other choice beside sanding or cleaning the part.

There’s one way only to avoid all these problems (beside using an airbrush or a spray can, of course), and I know that what I’m going to say might sound obvious: you must get, when you take paint out of the bottle and water it down, a viscosity which allows you not to get hills or grooves and, at the same time, avoids paint running and spreading around because of gravity. Practice and experimentation are really the only ways you’ve got to learn about the characteristics of your paint. Once you are familiar with these peculiarities, you’ll be able to decide by yourself when paint is ready to be used, but remember that a perfect paint is quite difficult to obtain.

Edges do represent another great trouble when painting with brushes. The edge (I don’t mean the U2 member...) somehow breaks the big paint drop and creates two smaller drops along itself. The result is that an incredibly small line of the edge's color is perfectly visible between the two near layers of paint which were born in that way. This sometimes doesn’t look bad, and may even be kept as a good depth effect instead of weathering.

Fig. 8: Thin Edge of Plastic Color Visible Through Paint.

If the result isn’t good enough for you, simply let the paint dry perfectly, paint the edge again with the same color by using a smaller brush, then hold the piece with the newly-colored part down and patiently let it dry for some minutes even if this might be boring. Gravity will this time help you to make the paint run towards the edge and stop in place. But be careful again, as using too much paint creates a round shape along the edge which might look very ugly. Instead of a thick layer of paint, use two or more ultra-thin layers, and your edge will be painted perfectly, even if this might require an awful lot of patience. Please remember that this touch-up operation could be useless if you think you’re going to gradate or weather the rims with the double color technique I’ll speak about a few lines below, as the unwanted lines will be covered with the gradation colors.

Brushes are quite good, and obviously better than and airbrush or cans, when you’ve got to paint details. The technique isn’t too different from what we saw before, but here the selection of the perfect brush dimension is even more essential. A 0/2 brush can sometimes be even too big if you’ve got to paint, for example, a Gundam’s head vulcan cannons, which are often molded in the head parts even in many MG kits. Nowadays ultra-thin brushes (0/10, for example) are available, and they’re perfect for the job. They’re also a little harder than usual brushes, and this makes them work like the nib of a Gundam Marker. Just remember your paint must be this time a very little denser to be taken on the brush, otherwise it will spread all over as soon as you’ve painted it on the part. However, it is difficult to obtain a perfect contour of the part by using a brush only. It is quite normal that a little colour may go across the limits of the part you’ve painted. If it is a very little mistake along the contour, remember that these parts usually need inking, so the little mistake will be covered with Gundam Marker ink. There’s no reason, therefore, to be too worried about this. Please notice that details on some very small parts may sometimes be painted more easily before removing the piece from the sprue, as I did with Gundam eyes in the picture below. In this case, the part to paint is far away from the clip points, and only the central section of the piece will be visible when the model’s done, so I painted that section only. Holding the piece while painting was very easy!

Fig. 9: Gundam Eyes, Painted with Tamiya X12 Gold Leaf. Imperfections Corrected with a Fine Nib Pen.

Even this time, anyway, modern technology has given us something better than brushes to paint the smallest details too: Gundam Markers and fine nib pens. Just as before, there’s nothing wrong in using brushes when painting details on a Gunpla, but I can’t deny that pens and markers really do the same job better than brushes. Once again, therefore, if you’ve got the opportunity to use a marker instead of a brush, do it, and your results will be better with little effort.

Gradations and Hues
Brushes are still essential when you deal with gradations and hues, that is when a color becomes another little by little, for example a red turning slowly into orange and later into yellow. Brushes in fact let you use two (or more) colors at the same time, and even let you mix these colors a little after you’ve started to spread them over the piece. If you’re familiar with miniatures and RPG painting techniques, these skills can be also used on bigger models like Gunpla, but, in my humble opinion, a little more effort can be made to make Gunpla better. This operation, of course, can be done both if you painted your first layer of color with sprays, or if you did it with brushes.

Fig. 10: An Example of Gradation

As far as I know (but I admit I have very little knowledge about this), gradations and hues on smaller miniatures are made by painting a little color on a dry layer of another color, and by spreading the color on the part so that the new layer becomes thinner and thinner, and the lower color becomes more and more visible. Let me say it again: if you’re familiar with this technique, you can use it on Gunpla too and get great results. But I must say that working with two different wet colors on this kind of model produces better effects. I was told actually, by a friend who has painted small miniatures since 1994, that gradations are often obtained with several layers of paint (sometimes even seven!), from the darkest to the lightest. Unfortunately a Gunpla has got so many panel lines that it is nearly impossible to use more than three coats of paint without filling these lines almost completely and spoiling the model (I’ll return on this topic a few lines below). Instead, if you learn how to work with the two-colors technique, you don’t use more than two layers of paint (the main one and the gradation one). Thus your inking lines will still be perfectly visible and easily over-writable. By the way, this technique comes directly from my mother’s pottery painting skills.

After painting the main color, actually all you have to do is paint the part you want to make a gradation on (usually the rim, but you can do this on any part) with the secondary color; then, at a little distance (depending on how large you want to get your hue), painting a parallel line with the main color. After this, slowly push with your brush a little of the secondary color towards the main one, and do the same in the other direction. Brush gently and carefully mix until you get the intermediate colors, and all’s done. It sounds easy, but I admit it is not. But it isn’t so difficult as you might imagine, and here too experience is the only thing you must have to get a good result. The only way to get this experience is to try the technique, even if this time a good effort is required.

The following figures illustrate this process:

Fig. 11: Spare Part Painted with Main Color.

Fig. 12: A Brushstroke of Liquidy Secondary Color Applied.

Fig. 13: A Stroke of Liquidy Main Color Applied.

Fig. 14: The Colors Are Brushed Together.

Fig. 15: Carefully Mix the Colors on the Piece, Creating Intermediate Gradations.

Fig. 16: Completed Gradation on One Side.

Keep these points in mind too:

1. As mixing colors on the piece itself takes more time than painting a single and uniform layer, your paint must be a little more liquid than usual;

2. Remember that even now drop rims are the first part that dries, so you must prevent the paint rim from drying by keeping the part wet with your brush. Otherwise, you’ll get some unpleasant lines you’ll have to cover with a little more paint (this is quite common anyway, and nothing to worry about, as this covering is usually quite easy and it happens almost immediately if you go on painting the gradation);

3. Because of this, the part you’re gradating can’t be too large. If it is (a full shield, for example), simply divide it in sections and start doing one section at a time;

4. Remember that, while mixing paint on the piece, it is not necessary to clean the brush too often, as you usually do when passing from one color to another. (By the way and going a little off-topic, when you have done with one color and you need to use white later, I suggest changing also the water you use to clean your brushes, because a dirty water, even a little bit dirty, will change a little the hue of your white).

Gradations on Gunpla are usually made with black along darker rims and another color, depending of course on the pattern of your model. From this point of view weathering can also be considered as no more than a gradation, and can be perfectly and successfully made with this technique. If that’s your aim, let me suggest using on white parts 50% grey instead of full black. This will make a softer hue, perfect to get a good depth effect that doesn’t look too strong.

Fig. 17: Fully Weathered MG Wing Gundam Zero Custom

The model in figure 17 was shadowed using the two-color technique. The hue on the white parts was made with Lifecolor gloss white and Lifecolor closs 50% grey on a white base (Tamiya gloss white X1). The red parts were painted with Lifecolor gloss black and Games Workshop bloody red on a base of Tamiya gloss red X7. Please note that, as the Games Workshop red and the Tamiya one didn't match, I painted an ultra-thin coat of X7 over the gradations to make them more uniform with the base. It worked!

Of course, anyway, you are free to paint normal hues and weathering gradations with any color you like, and this is a great advantage this technique provides to you: you do not depend on already made color sets that maybe don’t let you have that peculiar hue you’ve always dreamed to have on your own customized Gunpla. Just remember that different brands' colors don’t always mix perfectly, so you should try how your paints behave before starting to make a full gradation. You can also get a gradation from a matte color to a gloss one and vice versa without any trouble, but avoid making a hue with metallic and a non-metallic colors, as it will be a real mess and nothing else (if you succeed in doing so, all my compliments).

Fig. 18: MG Wing Zero Custom's Shoulder, Weathered with White to Grey Gradations to Create a Shadowing Effect.

Also, this technique lets you skip another passage maybe you’re not familiar with: topcoating. Actually weathering compacts do require topcoating, as otherwise they’d be removed too easily every time you just take your model in your hands. If you’re not in the habit of topcoating your models (even if it is highly recommended by Martin), as this technique does no more than adding a thin layer of paint over the model, weathering colors are anyhow fixed on the Gunpla, surely much more than if they were with a simple sweep of weathering compacts.

Remember that inking must be done after painting gradations, whereas you can do it before weathering if you choose to do it with weathering sets.

Again and again, here too compacts and sets are a great help in painting a Gunpla perfectly, but in this case I do suggest making this little effort to go further with common skills, because the rewards this effort provides are really worthwhile, once you master just a little a double color technique.

In the end about hues, it might happen that a color line (a brush stroke, actually), invisible bare–eyed, suddenly appears in a macro picture you’ve taken to show to your friends in the net.

Fig. 19: Gradated Model Viewed At a Distance.

Fig. 20: A Close-Up of the Same Model, Showing Visible Brush Strokes.

You must not worry about this, as it is quite normal. Color gradations are often visible to human eyes exactly because two little portions of different colors are quite near to each other, so the blasted line must not be cancelled if you really don’t see it even if you’re near to the model (4-5 cm). Just take a picture from a little further, and any problem will be at least less noticeable.

Let me give you an example of this: your printer has got four colors only, and all hues are created by pouring some ultra tiny drops of the basic colors one near another. The perception of green is obtained, for example, by seeing two nearest drops of yellow and blue. Now, if you imagine you can magnify this green effect hundreds of times, you’ll see again the original blue and yellow ink drops. The same thing might happen with your hues: one of them can be made visible because two different colors are so near that they look like one color only. It is normal, in my opinion, and absolutely not to be worried about!

Finally, let me say a few words about a topic which might concern every way you choose (sprays or traditional brushes) to paint your Gunpla: the usage of primers.

Even if they were fully necessary until a few years ago, and many people still suggest using them today too, I don’t think they are so essential nowadays, as modern paints already have got a little primer in them. Moreover when you’re painting a Gunpla a primer is another layer of paint you spray or paint on the model, and even if the coat is very thin, it might somehow fill panel lines just the same, and make inking more difficult or even impossible.

But there is one time when a layer of primer becomes necessary: when you’ve got to paint a totally different color on the piece. In 1/100 MG RX78-2 ver. 1.5 kit, for example, some parts of the core block (which should be white, red and blue) are molded in black. As white, red and blue paints are commonly a little transparent, a layer of white primer (your common white will do the same, if you haven’t got a primer spray can) is essential; otherwise your color will be seen very little on a black base.

Fig. 21: Core Block Parts Molded For Some Reason on a Black Sprue.

It must be pointed out that this transparency of the paints (if you’re familiar with Tamiya blue X4 and red X7, you perfectly know what I’m talking about) can be successfully used to get some peculiar effects, depending on the primer base you decide to use. It is said, in fact, that a white base makes models more cartoonish, and that a black one makes them more realistic. I wouldn’t be so certain about how realistic your colours will appear, but I’m sure about this: the primer always changes the hues final color on the model, and you can use this feature to make some parts more glossy and lightened, and to get others a little darker or more matte, depending on your personal taste. Yet, keep in mind this: as paints are always a bit transparent, using a white base is never a mistake, as all colors will be visible over it even with one coat only, while other primers might somehow hide one single coat of the main color, so that you should paint another and another, but too many paint layers may hide some details and fill panel lines, as I said above.

Personally I also paint a little primer on small pilots’ miniatures. Inking is not required on them, and  here something that helps your paint to stick better and faster is essential, otherwise your little heroes will soon become a mess of mixed colors and nothing else!

One little final consideration. Have you seen my Mazinger Z model in figure 19? Well, please, pay attention to the white belt. This belt is made with a soft white plastic, and when I first painted it with white gloss, it strangely and with no apparent reason at all turned pink. I removed the paint with a little acetone, but the pink color was formed on the plastic, not on the layer of paint, and there was no way to remove it. This pink was strongly visible under even three coats of white paint, so I eventually cleaned the whole  belt, and painted a layer of black primer (actually Lifecolor gloss black), which finally covered that blasted pink fully. Thereafter I could paint my white on the belt and later detail it with the yellow buckle. Sometimes primers help to hide these plastic imperfections, but I really hope I’ll never have to do this on too detailed a piece, as I would risk too much to cover details and lines.

Well, I think all’s said and done. I hope this little tutorial of mine won’t spoil Martin’s site. I did my best, and I’ll be glad if somebody visiting this little site should find my work interesting and above all useful. Just think that, even if I started Gunpla modeling in March 2002 with an HG 1/100 Wing Gundam, I first painted fully a Gunpla (a 1/100 HG Wing Zero) only in April 2008, after visiting (almost by mere chance) this corner of the Net. So, I do hope too that these lines will help someone else to find the guts to take an extra step and a little effort, as I did.

Don’t think you will never able to do it simply because you haven’t got an airbrush, cans or weathering sets. With a little courage and the real will to try a new experience, everybody can become a good Gunpla modeler, even by using an old set of brushes instead of more modern tools.
(But not too old, if you don’t want your Gunpla to be full of broken brush hairs stuck in the paint!)

Bye everybody!

Alberto from Italy, fan of Gundam and other Japanese robots since 1978. (The first robotic cartoon broadcast on Italian television when I was three: UFO Robot Grendizer, also known as UFO Robot Goldrake in my country.)