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Dot Filters- Demystifying The Spots

As I’ve grown as a modeler over the years, learning new techniques for finishing my kits has become my main focus. While research of a subject, attention to the little details in a build, and of course having fun are all important, those have taken a lower profile in my progress. It has been refinement of technique that stands out as the thing that I really spend a lot of time working on.

After this article was first published, I created a video to demonstrate the dot filter technique. Take a look – and please be sure and subscribe to my channel!

Some techniques come easily. Sanding a seam line is… well, pretty much self-explanatory. Certainly there are refinements one can learn along the way, but the basic theory is much like hammering nails. You don’t so much learn new ways of doing it as much as simply getting better at it.

Still, others can seem a bit daunting when they are first encountered. Perhaps it is the way it is described, or the materials used, or even the source. (There are sketchy modelers everywhere… any idiot can start a blog and a Facebook page and call himself… oh wait… nevermind…)


I’ve had times where I’d hear of a technique, watch multiples videos of it, read several explanations,  and yet even after all of that, still have a feeling of “I’m not quite sure I know what I’m doing”. (Which, to be honest, is something I feel ALL the time, now that I think of it.)

At some point a few years ago though, I realized a simple fact- it’s plastic. It can be sanded down, primed over, and painted again. Sure, it can be a real pain to do so. But I realized I should not let fear of “messing up” what is basically a plastic toy hinder my growth.

When I first encountered the “dot filter” technique, I thought it was a bit nuts. Place loads of colored dots all over your model and streak them around in a horrid mess. Brilliant!

But being the modeling monkey I am, I thought I’d give it a try. And I found that I liked the results. The trick is knowing when to use the technique, and in what quantity.

So What Is A Dot Filter?

I suppose at this point it might be helpful to provide some explanations of terms. Many modelers talk about a wash, shade, pinwash, or a filter, and quite often the line between them can be blurred. For the purposes of clarity, I’ll submit that we classify washes, shades and pinwashes as techniques that make particular details, such as recessed lines or raised edges, stand out. They provide some sort of color contrast or delineation. 

Filters, on the other hand, are designed to impart some form of color “shift” to a surface, and are not focused on defining detail. 

If you’ve ever seen how colored lights can change a subject in a photo- that’s basically a filter. There is something between your eye and the subject that imparts additional color, changing the overall tone of everything.

Of course, this begs the question of “why not just start with that color to begin with?” If all you are trying to do is make a fairly monotone appearance, that is a valid point. 

Where a filter comes into its own on a surface is helping “unite” colors. For instance, say you have applied a green and brown camo pattern. It will look a bit stark perhaps, or the brightness of one color may overpower another. Choosing an appropriate filter color (note to self: save that idea for another blog entry 😉 ) will help make the two colors seem to fit together, to have a similar tone.

Filters can also impart a dusty look, or a darker, heavy look. 

However, when thinking about our technique under discussion, using filter theory in dot format gives us something a bit more.

Taking Cues From Real Life

Look around at any large object that’s been outside for a while. There will usually be streaks of some sort. These can come from cycles of rain, dust, pollen, bird poop, sun fading, or any other abuse nature can provide. The rain streaks layers of dirt that have settled, that dirt forms into time little “channels”, then later dirt and other materials collects there. Dew forms in the morning, and runs off, making more streaks. The cycle continues.

When viewed from a distance, even just 20-30 feet away, most objects will take on a multi toned look. Sure, my car is “red”… but there are probably hundreds of minor variations over the surface of the car. (It’s in sore need of a washing!)

So the dot filter technique is an attempt to impart those types of streaks on a model. Simple as that.

Yes, Yes, All Good- But HOW?

Right. Let’s get to it.

I start with a model that’s been painted in the basic colors. For this particular 1/48 Eduard Spitfire Mk. VIII, the upper surfaces are painted with Tamiya flat acrylics. Working over flat or satin paints works better in my experience, as a glossy surface has no “grip” for the dots to cling to.

For my dots, I picked a few Ammo of Mig Oilbrusher colors. Any oil paint will will do – oilbrushers or traditional tube paints. But it must be oils- acrylics dry too fast to work well.

I also had my trusty aluminum palette, and a few cocktail sticks, one for each color. I picked a fairly ratty but soft and wide brush for the work, and I had my odorless turpenoid thinners standing by.

Please note- if you use enamel paints as your base, this method can interact with the paint layer. Adding an acrylic based coating of matte or satin over the top may be required. (I’m an acrylic kind of guy, so I’ve not had to worry about that.)

With my materials collected, I’m ready to get started. I place a blob of my chosen colors on the palette. I like to set each cocktail stick into each color so I don’t get them mixed up.

My choice of colors here is simple- I want to impart a dirty, streaked look, not so much a color shift. So I focus on grays and tans and browns.

I start with my lightest color, because it will generally be the most visible. Using the cocktail stick, I place dots of color all over the wing in a random pattern. Now- some explanation of random is in order.

When I say “random”, I don’t mean “willy nilly”. While I do want to just place the dots without focusing on specific points, I do think in terms of density – how many dots per inch? Again, I don’t try to place them precisely, but in order to make a more natural look, some thought to distribution and density must be given. For the first set of dots, I also count how many dots I do. This helps me determine the appropriate density for the later colors, and even lets me adjust the balance.

For the next color, I place an equal number of dots, again- being random in placement, but with an eye towards the distribution and density. If dots are next to each other, that’s fine. But I want to make sure I don’t overload any one area, or miss another. (UNLESS that is the effect I want to impart…)

As I get to the darker dots, I wanted to reduce the density a bit, so I used fewer dots. I spread the distribution around a bit more also. (Later weathering steps will introduce specific stains and streaks for oils, mud splashes, etc.)

When I’m finished, I get a wing that looks as if it had sat underneath the bleachers at a pigeon’s game of football. 🙂


Now comes the part where most people run in horror. I grab my brush, and start streaking.

No, no, no… not that kind. I keep my clothes on. Streaking with the brush, ya weirdo…


First, I dip my brush into the thinner, and then dab off most of it on a paper towel. You don’t want it dry, but it should not be too moist. If you’re doing it for the first time, go with the “less is more” idea until you get some feel for how it works.

The key is to start at the forward/top part of the surface to be streaked, and pull back/down in straight, even strokes. I don’t do it fast- it’s a fairly slow, deliberate motion. The first time you try it, go abnormally slow, only building up as you see the effect speed has. If you just go into it as if you were doing a quick dry brush, all of the colors will blend and turn into a mess. 

Straight back/down, return  to the front/top, move over a bit, and do it again. After the first pass, you will be convinced you’ve destroyed your model.

Don’t worry- stick with it. Continue the process, pulling the paint back, moving to the next row, and doing it again. Over and over. 

I like to occasionally dab my brush in thinners, wipe off any excess oils, and then moisten it again and return to the work. I generally do this every three or four passes.

At some point, the streaks will begin to get lighter and lighter. It will be up to you to determine how light you want to go. The best I can tell you with regards to that is experience matters. You must do this technique more than once to really get the feel for it. It’s not hard by any stretch, but only through a variety of applications over time will you begin to really make it work for you. The first time you do it, you may feel as if the technique is controlling you. But stick with it!

Eventually, I ended up at the point I was going for- a slightly  streaked look that is not too overpowering. One image shows the results with the thinner still wet, the other, after about 20 minutes of drying time.

So That’s It?

Yes… but….

Here are a few things I’ve found to be helpful considerations:

  • On the tailplanes of an aircraft, it can be very easy to get the density and distribution way too heavy. While the surface is smaller, your brain may be thinking “Lots of dots! Lots of dots!” Keeping in mind that count of dots discussed earlier really helps.
  • On fuselage sides, I like to place most of my dots along the top of the fuselage, and draw them down on either side. Because the “pull” distance of the streak is so short, this allows for better control.
  • On armor, Gunpla, Warhammer, or other non-flight type vehicles, the principles are the same. However, because these aren’t subject to high-speed flight, think in terms of how rain flows down, and where dust and dirt would collect.
  • If a surface is horizontal, such as the upper deck on a tank, I find I like to use a “dabbing” or stippling motion to spread the colors around.
  • Check the surfaces that are not being streaked at the time. On this model, after I’d finished the upper wing, I needed to go back to the lower wing, as some of the oils had stained the lower edges. A quick swipe of a cotton bud soaked in thinner took care of that.
  • Color choice is critical. While you can pick any color you like, sometimes more primary colors will induce tones that are not wanted. Until you get a good feel for the technique, focus on more muted colors that don’t stray to far from the base colors.
  • If you do make a mistake (or a complete botch up of it), don’t worry. Grab a paper towel, moisten it a bit in thinner, and wipe the paint off. You may have to wipe for a while, but it is very recoverable.
  • If you realize the effect is not as intense as you wanted, let the oils dry, and do it again. 

Wrapping Up

I normally allow a dot filter layer to dry for several days. Once it is fully dry, I will add a varnish layer over it. What type- matte, satin, or gloss, will depend on what I plan to do next. On this particular model, I will be adding decals next, so a gloss coat will be applied. Once those are on, they will be sealed with another varnish coat of satin, to allow for additional weathering steps.

The ultimate key to this technique is trying it.  I spent quite a while speculating on it, but it was only when I actually applied it – and made a bit of a mess the first time – that I began to see where it could be applied, and also where it was not as helpful.

Also, there are many minor variations on this technique. I have shown how I do it. I would never claim this is the right way, just a way to do it. You may find variations that are helpful to you. (Please pass them on to me!)

And be sure and check Youtube for videos demonstrating this technique. Sometimes watching someone do it is really helpful. (But hopefully having some idiot write about it is also useful… hopefully… 😉 )

While I’d never say this is the end all be all of weathering techniques, I believe it forms a sound basis for later steps to follow. As you use it, you’ll better understand how this technique interacts with others, and be better equipped to get the result you want on any model.

21 thoughts on “Dot Filters- Demystifying The Spots”

  1. Great article Jon, I have been looking for an explanation of the technique. I bought some artist oils to try it with, will give it a go on some test parts. Have you ever done this on a NMF finish to give it some tone? That is one thing I am really interested in trying.


    1. Hey Steve – thanks for reading my blog, and for the kind words!

      I’ve tried it on a few NMF finishes, and while it does work, technique is key. The method works best when the paint is matte, and has a bit of “grip” to it. Most NMF finishes are quite “slick”, so it will be a fine line between “tonal variation” and “smudges”. 🙂

      It is a method I’d like to explore further. I don’t do too many NMF finishes, actually, as I’ve never found a product that I’m able to make work satisfactorily. If you give it a try, let me know how it goes!

  2. Great little article – I’m a bit weird, I much prefer written explanations with photos, rather than videos. On Youtube, you invariably hear either terrible background music, or the narrator just goes on and on and on – that’s assuming you find a decent video, because a lot of YouTube videos about modelling are not great.

    So, thank you!

    1. Thanks Dean! I’m glad you found it helpful.

      I’m like you – I like text! And even though I’ve started doing videos, I plan that everyone will be accompanied by a full text/photo article. I think that will really help convey the topic across a broad variety of learning styles.

      I can promise no terrible background music, but I may go on and on… 😉

      Thanks again!

  3. Great article. I’m about to try it!
    One question, though. Why weather before the decals are applied? Surely they weather at the same time as the rest of the plane?

    1. Thanks Andy! I’m glad you like that!

      It depends on how you want the final look. Because I wanted this to look heavily weathered ultimately, I opted to streak the paint only first, and then later apply the decals. More weathering steps were added later – these streaks were the first layer. You can see the final result here:

      There are times I do the decals first, and then the streaks – so both can work. But I felt such a heavy application would be too much at that stage for decals.

      Also, in this instance, it was more practical from a publishing standpoint to focus on the technique alone.

      Be sure and subscribe to my YouTube channel – I will have a video demonstrating this technique (on another model) that will be going live Feb 7 2020.

      Thanks again for reading my blog- have a great day!

  4. Jon-

    I hope this finds you and yours well during this time of craziness…

    Is there an advantage to using enamel thinner vs odorless mineral spirits (starts with a ‘T’, ends with an ‘oid’, sounds like burp in the middle)?

    Do you prefer to filter over gloss, matte, or satin finish?

    Thank you for the excellent website, GREAT instruction vids, and a place where I can look at models and remember just how lousy mine truly are!

    Yours in Plastic-

    Matt K

    1. Thanks Matt! I hope you and yours are also well. Definitely different times isn’t it?

      And thank you for your kind words – I am most grateful! I’m glad I’m able to share things that are useful. 🙂

      To be honest, I’m not sure what the chemical difference is between the “odorless enamel thinners” and “turpenoid”. I have found Material Safety Data Sheets for several brands of turpenoid, and they list “petroleum distillates” as the ingredient. I have not been able to find an MSDS for AK, Ammo, etc., odorless thinner.

      However, in use, I can find no difference. I’ve used Weber’s Odorless Turpenoid, Ammo Enamel Odorless Thinner, and AK’s brand also. I’ve thinned many brands of enamels and oils with all three, and the results were the same. I’ve been told that the modeling specific brands have some sort of drying or flattening agent, but in observing the results, I can’t say I even see that. And this is something I’ve been doing for years.

      I finally decided to just stick with Webers, as I can get it much cheaper on a per ounce basis than modeling specific products.

      Regarding the gloss/satin/matte question… I’ll have to give a politicians answer – it depends. 🙂

      It basically hinges on what I will be doing after the clear coat, if I apply any at all. If you take a look at the video about weathering the Star Wars Occupier tank, I put the washes right down on the matt paint. I wanted to take advantage of the “spread” that happens, which makes for a grungy look, even after cleanup.

      If I want a more precise application, I tend to use a gloss clear coat underneath. This reduces surface tension, allowing the wash to flow and cling to detail, but makes for easy cleanup later.

      So I guess it all comes down to the final finish you are going for. Sometimes I even do it in stages… clean lines over a gloss coat, add a satin coat, and grunge it up more. The trick will be to experiment. I’m a big advocate of allowing yourself the freedom to “mess up”, rather than try and achieve perfection. Only with finding out ways to not do things will you learn the ways to do things.

      And please don’t be too hard on yourself… everyone is at different places along the modeling journey. All of us started at model number 1. We all try different things, etc. What I do is nothing special, truly. I’ve simply done it a lot. And I still look at every model I build and think “well, I could have done better.” So it’s not just a matter of a single model, but a cumulative of the total. I often like to pick something that I feel I’m not as good at, and make it a focal point of a part, a section, or even an entire model. That helps build the skills up!

      Whatever you do – have fun with it!

      Thanks again, and have a great day!

      1. Thank you so much for this great article! I finally understand the why and how of for filtering. Is it absolutely necessary to varnish if the oils have fully cured for several days? Inworry about occluding details with too many protective coats. Thank you and I hope you are well!

        1. Thank so much Jesse! I’m so grateful for the read and comment, and I’m very happy you found it helpful.

          As with so many other things, the answer is “it depends”. Even when oils may seem dry to the touch, there is a possibility that enough thinner can reactivate them. So care has to be taken with regard to that.

          Yet at the same time, I agree with you that too many clear coats can become a problem.

          One of the easiest ways to navigate this dilemma is to break up the weathering (if possible) by the type of weathering materials being applied. I often try to work things out so that I can do all the acrylic weathering first – because it dries fast – and then do enamel/oils afterwards. This is what I think of as my “fast” method, because it allows the quick dry stuff to be under the slow dry stuff. Quite often I can arrange things so that once oil effects are applied, I have nothing left to do.

          If speed is not an issue, then switching mediums between steps can be helpful. For instance, I may add a dot filter with oils, and then after letting that dry sufficiently, I’ll add acrylic weathering products. These not only dry fast, but they also seal the oils in. This way I can (carefully) add more oils over that, then acrylics, etc.

          In the case where you’re weathering is all oils/enamels, you can still do some planning so that later steps don’t remove the previous ones – both by drying time consideration and careful application.

          Most of the time, if you’re not flooding the model with thinner, doing oil over oil, oil over enamels, etc., should not be a problem though. Take into account drying times, and if possible layer the weathering so the effects that rely on more thinner are the first to be applied.

          It’s all about build strategy!

          Thanks again for reading and commenting!

  5. Very good technique from the looks of it. I have used rock salt applied with a thin brush stroke of water followed by a VERY thin acrylic filter of white or brown then removed the salt once dried… but this looks like a better filter.

  6. Just making sure. Say I’m doing the following;

    Base coats with water based acrylics (Vallejo etc.)
    Color modulation with oil dot technique. (Ammo by Mig Oilbrushers)
    Weathering with enamels, pigments and maybe more oils. (Ammo/Ak enamel washes&pigments, oilbrushers)

    I’m pretty sure I need to put varnish on top of the base coats (even when lots of people say it’s not needed) before doing the oil dots.
    But do I need to put another layer of varnish after the oil dot modulation so that the upcoming weathering with enamels+thinner won’t re-active or ruin the underlying oil dot modulation?

    Thanks for the help!

    1. You can do that. But I’d suggest it’s two coats too many – possibly. Here’s why.

      If you put down acrylics first, once they are dried and cured, oils and enamels won’t bother them a bit. The only reason it might be good to put down a clear coat after acrylics is if their finish (flat, satin, gloss) is not what is needed for the oils and enamels. As most acrylics are flat or at least satin – which is perfect for oil dots – there really isn’t much reason to add it. Unless you’ve gloss coated it for decals, it should be good as it is.

      Once you’ve done your dot filter application, you could put down a clear coat for later oils and enamels. However, to do that properly requires that the oils be completely dry and cured, otherwise you might get “crackling” in your clear coat. And once the oils are fully cured and dried, it would take some really heavily slopped on oil and enamel work to dislodge them. Still, as a “safety”, it certainly doesn’t hurt to add it after the dot filter. I’d suggest a satin coat if you were going to do that.

      Hope that helps!

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