Are you looking for the best primer for painting plastic or metal miniatures? The best primer for painting miniatures depends on the surface material. Some primers work best on plastic, whereas other primers work best on metals. In principle all primers work the same. Primers are used as a preparatory coat over unpainted metal, plastic, or resin and prevent the absorption of subsequent layers of modeling paint. Many primers for miniature and models also act to smooth out imperfections on the unpainted surface.
Every miniature painter or fine scale modeler should consider using the best primer for their project. Believe it or not, primers can have specific-use scenarios.
Not all primers are the same.
Here are the 10 best primers for painting plastic and metal miniatures:
- Citadel Model Primer
- Citadel Paint Contrast Spray: Grey Seer
- Krylon Ultraflat Primer
- Liquitex Neutral Gray Gesso
- Army Painter Primer
- Vallejo Surface Primer
- Tamiya Surface Primer Spray
- Testors Enamel Primer
- Badger Airbrush Primer (Stynlrez)
- Rust-Oleum Automotive Primer
I’ve tried each of these primers over the years. It’s fun trying out new tools and art mediums. My favorite overall primer for my modeling needs is Vallejo Surface Primer.
Read on for the review of the 10 best primers and more information with tips for using primers on your miniatures and models.
What is a Primer?
Primers form the prerequisite foundation for any painting. A poor foundation leads to problems later. I use many brands of miniature paints for my work, e.g., Scale 75, Citadel, Master Reaper Series, P3, Badger paints, but only keep a few primer types on-hand.
In comparing different primers to paint miniatures and models, you might be wondering why you need a primer.
A primer is a substance you use to coat an unpainted surface to prepare it for subsequent layers of modeling paint.
It doesn’t matter if you’re painting on plastic, metal, or resin miniatures, a primer coat provides a universal surface for you to work on.
If you’re into make-up and cosmetics, you already know why you need a primer. A primer covers the skin to prevent the make-up you place on top from being absorbed into your skin. Another benefit of primers is that they help smooth out the texture of the surface.
A primer allows you to confidently apply an artistic medium, make-up or acrylic paint, and improve your ability to control how it looks.
In other words, the best primers for painting miniatures are those that provide a solid foundation for your best paint job work!
Best Primer for Plastic Miniatures?
The best primers for plastic miniatures in the 28-35mm scale are generally spray-on type primers. For larger miniatures, you can use almost any primer, as you’ll see why below.
Ultimately, the purpose of a primer is to provide a thin even surface in preparation for paint.
You want to avoid obscuring details. This means you want the first layers of the primer coat to be super thin. Each layer of primer coat you apply to a plastic miniature will slowly build up in the recesses.
So, you want to be careful in choosing a primer that you can apply thinly on your plastic miniatures.
A spray primer is the best choice, since spraying is the easiest way to apply thin layers over a model.
Spraying also prevents bubbles from forming on the surface of your models.
For example, Tamiya makes a rattle can primer for miniatures that is highly popular for professional and competitive miniature painters. Vallejo makes a great surface primer (my favorite) that you can either brush-on or use with an airbrush.
Note that there are times when you want a brush-on primer (more about this below). For example, when you have limited space for a spray booth, indoors in an enclosed space, or in a public convention where spraying might not be appropriate. Aerosol or rattle can primers also pose an issue because of the odors and potentially harmful vapors. These should be generally used outdoors (in low humidity for best results!)
Best Primer for Metal Miniatures?
Similar to primers for plastic miniatures, the best primers are those that you apply using a spray application. This provides the thinnest, most even coats on your models. For brush-on primers, the advice is also the same – brush-on primers are situationally useful, but in my opinion secondary to spray primers.
Metal (and resin) miniatures pose a unique challenge for primers!
There are two reasons for this.
- Metal and resin miniatures may have a greasy, mold-release substance on them that repels primer and paint from sticking.
- Metal and to a lesser extent resin models are prone to scratches and deeper bumps, because their surfaces aren’t as flexible.
First, metal and pewter miniatures are cast in molds.
This means that metal, pewter, or even resin models have a lubricant or mold-release substance on them.
This greasy, usually invisible layer of mold-release that helps the miniatures pop out of the molds. But, this mold-release lubricant repels primer and paint.
Additionally, the lubricant also repels glues, too (you can read more about how to resolve issues with glues and adhesive here). So, this may even be why you are having a hard time assembling pewter models. Glue doesn’t adhere well to that residue of mold-release.
The solution here is to wash your metal and resin miniatures with soap and warm water. Personally, when I have a lot of models or miniatures to wash in this manner I use an ultrasonic cleaner filled with soapy water (see my article on cool ultrasonic cleaners, which I also happen to use for cleaning my airbrushes).
You should apply a primer only after washing and drying your models.
Second, paint and primer on metal miniatures tend to get scratched easily.
This seems obvious because metal miniatures are a much harder surface. Metal and resin models don’t have as much flexibility as hard plastic models.
The best primers for plastic miniatures, such as those from Games Workshop Citadel miniature lines, may not be the best for metal surfaces.
For metal miniatures, you want a primer that hardens and for lack of better words, “sticks better” to the metal or resin surface. This means you probably want an enamel-based primer. Enamel is a much harder substance than the polyurethane material of a lot of non-rattle can primers.
To my knowledge, I don’t know if there is an airbrush ready enamel-based primer designed for miniatures. The best airbrush primers for miniatures are polyurethane water-soluble solutions.
An Alternative to Enamel-Based Spray Primers is the Traditional Gesso
Gesso is especially useful for metal or resin miniatures.
Here’s why: Gesso is a hard compound, usually plaster or glue-based, that is traditionally used on canvas, or stone and ceramic sculptures, before painting. It effectively forms a hardened surface with the model you’re working on.
In some cases, Gesso has rougher texture to it, or ‘tooth’, that is useful for some characterful types of miniature painting. If you paint models or miniatures with oil paints, you’ll see Gesso as especially useful.
Gesso is inexpensive, forms a protective surface for applying paint, and smooths out surface imperfections.
Gesso comes in many forms, but they are all brush-on type primers. Many miniature painters use gesso for priming miniatures and models.
Liquitex Gray Gesso is my preferred gesso medium for priming larger models and terrain pieces. Not only is it inexpensive, it is resilient to scratches and stretches out as it dries on models, providing a very smooth and pleasant surface to work on.
Best Cheap Primers for Large Miniatures and 3D Printing
For the best cheap primer for miniatures you can take a closer look at generic household or automotive primers. I’ve tried regular spray-can primers for painting outdoor furniture like Krylon and Rust-Oleum primers. They are generally less costly and come with a lot more primer for your money.
Be warned, however, that these cheaper primers do not coat as thinly as dedicated hobby primers for modeling. Spray farther away and in very light misting coats.
I’ve had good results with cheaper primers for terrain pieces.
Cheap spray primers are especially useful for MDF terrain, laser cut parts and terrain pieces, gaming boards, and 3D printed pieces, which are larger than smaller scale models.
The nice thing about automotive primers is that they are designed specifically to smooth out imperfections on surfaces.
This is great for 3D prints and large models. After these primers dry, an automotive primer can be sanded to further even out the surface in preparation for paint.
In conjunction for gap filling (see more about this here), an automotive primer can make a model or miniature resilient to damage because how “sticky” or adhesive it is to the surface.
Be Careful with Cheaper Primers
A word of caution about using cheap primers that are not designed for miniature and scale modeling work.
Cheaper primers, e.g., automotive or outdoor furniture primers, are formulated to cover surface fast. This means that these primers are created to spray-on in thick layers.
A single coat of automative or wood furniture primer, especially aerosol delivered primers, will quickly obscure fine details on a scale model or wargaming miniature.
Although I mentioned this is attribute of cheaper primers is advantageous for 3D prints (which have fine build layer lines you want to hide), or large terrain pieces; for miniatures that have small details, I would suggest you avoid non-hobby grade primers for miniature painting.
For painting miniatures, choose a primer that you can apply in thin coats. Not only does thinly applying primer help you avoid covering up fine detail, these modeling primers give you a lot of control over how much you want to apply at a time.
Maybe you do want to hide fine scratches, bubbles, or imperfections on your models. Other times you’ll want the finest mist of primer to keep all those beautiful facial lines and wrinkles intact on that 75mm scale resin bust.
Your call. When in doubt, thin your primer (just like you would your paints).
What About the Adhesive Formulation?
In general, almost all primers produced by dedicated modeling companies have primers designed specifically to adhere and “smooth out” as they dry on plastic (or metal) miniatures.
Companies like Vallejo or Tamiya have been in the business of making primers specifically formulated for their model kit product lines.
For miniature painters, this is a huge benefit because we don’t need to get into the nitty-gritty of how they work. I write more about how primers work throughout this article.
Interestingly, some spray primers from Citadel and Army Painter are colored with the most popular model paint colors. For example, you can get “flesh’ colored primer if most of your model is flesh-toned.
MORE: HOW I SPEED PAINT MODELS
This can help you speed up your overall paint job by priming and painting the base coat at the same time!
For my personal work, I like separating the priming stage from my painting stage. But, everyone has their preferred workflow.
The “Acrylic Paint Sandwich”!
Primers aren’t formulated like miniature paints, which are generally acrylic polymer-based mediums.
In contrast to acrylic paint, primers do not absorb water after they dry.
An acrylic layer of paint can absorb moisture, which can lead to subtle warping and expansion of the paint. Hence, you also should use a good varnish seal to protect your models when you finish painting (see more info about best uses for varnishes and my thoughts here).
The best practice for painting a miniature requires that you “sandwich” your acrylic paint between a primer and varnish. In this scenario, your paint job is protected from being absorbed into the model’s surface (if it is porous, some resins for example), and the external environment.
Tips for Airbrushing Primers
The simplest way to airbrush a primer is to use an airbrush-ready primer, such as the Badger’s Stynylrez airbrush-ready surface primers. Simply add a few drops of the primer to your airbrush, set your air pressure to about 25-30PSI, and spray away.
Note that if you’re using an airbrush with a nozzle size of 0.3mm (or smaller), you may want to thin your primers with water or dedicated thinner mediums.
The best practice for airbrushing is to thin your paints or primers to the consistency of whole milk. You may need to add several thin layers to properly and evenly coat your models this way.
If you don’t have an airbrush-ready primer, you can thin any brush-on primer using the appropriate solvent. In most cases, the proper thinner is simply water (1:1-3 ratio for my needs).
But, if you’re having trouble with using water to thin your primer, you can use an airbrush thinning medium. The one that I use to thin water-based polyurethane surface primers is made by Vallejo.
The Vallejo Airbrush Thinner is super versatile, because it is also useful for thinning model paints as well, acting as a flow-improver (check it out here).
Tips for Brush-On Primers
For brush-on primers, you just need to remember to be patient!
Bubbles can form if you try to apply thick layers of brush-on primer.
Use a large, flat headed brush and coat in thin layers. I use a cheap synthetic brush for priming and base coating models.
Allow each layer to dry before applying another coat. Sometimes a model might need 2-3 layers of a brush-on primer. It’s okay if you can still see the bare surface of your model under a brush-on primer.
Remember that the primer is simply coating the surface to help prevent your acrylic paint from absorbing into the surface. It’s also smoothing out the surface.
Don’t apply too many layers of primer. Each layer slightly removes details from the miniatures. In this way, using brush-on primers is kind of an art, too.
It is a technical skill to properly apply brush-on primer (which is why I suggested the best primers for miniatures are spray-on).
Overall, take your time when you apply a brush-on primer. You will get the best results when you are patient.
What is the Best Primer Color for Miniatures?
So, the question “What is the Best Primer Color?” is a good one!
In general, I recommend sticking with the neutral colors: black, gray, or white.
Although miniature companies have produced colored primers, they are expensive for what you’re getting. And, in general, you’ll be painting other colors on top of those first primer layers anyway. Most of those first undercoat colors won’t show up.
Here’s the bottomline:
The best color primer for miniatures is black, gray, or white depending on your eyes. Do you prefer seeing shadows or highlights? In other words, do you like painting something to make it lighter; or, would you prefer to darken a model as you make progress?
At the end of the day, it’s personal preference. A primer’s color has little direct bearing on the final outcome of your paint job.
Black is the Best Primer for Speed Painting!
If you are speed painting, black is the best primer color!
Here’s my thinking about this. Black lets you keep contrast easier on a model.
When you want to paint fast, maintaining contrast is key.
Black primer lets you just paint lighter colors. The shadows are taken care of for you. You can let some of the primer show through in the shadowed recesses! This lets you ignore those parts of the model.
As a shortcut, black primer also lets you use zenithal highlighting. In zenithal highlighting methods, you either airbrush or use another white-color spray paint (this could be another primer or simply white paint) over the black primer-colored model.
This adds a “light source” from above the miniature. This is a very fast way to add contrast. When you glaze a color over this, you can achieve a beautiful saturated and contrasty model fairly quickly.
10 Best Primers for Painting Plastic and Metal Miniatures
The following are my recommended top 10 best primers for painting plastic and metal miniatures.
1. Citadel Model Primer
The Citadel Model Primer sells for about $21-23 per can. At first glance, it’s fairly expensive, but it is a good choice if you’re looking for spray-ready primer for plastic miniatures. My experience with this primer for metal miniatures is also good.
Make sure you shake this can thoroughly before use. And, for best results try to spray this rattle can primer in relatively low humidity at room temperature (25C or 70F).
Note that there are many colors of Citadel Primer. As mentioned above, each has a purpose. In my opinion, the black primer is the best in terms of quality of the primer surface. White colored Citadel Primer can be problematic because I’ve found it often leads to a bumpy, powdery surface.
The Citadel Model Primer is a primer that is useful for plastic and metal miniatures. It is formulated for Games Workshop kits, but can be used on almost any surface material that miniatures and models are made of. Because of it’s branding, this primer is usually found in most hobby or local game stores.
It’s a rattle can primer. That means it’s an aerosol based spray that should be used in well-ventilated area. For environmental reasons, aerosols aren’t great either. Because the can is under-pressure, you should be aware that storage in a safe place away from heat is important.
As a spray, you’ll also find that a lot of the primer is wasted if you’re not careful to direct it at a fairly large surface area on a model. I suggest spraying more than a single model at a time to make the most use of this primer.
2. Citadel Paint Contrast Spray: Grey Seer
The Citadel Paint Contrast Spray is about $25 online and more in stores. It is a new formulation designed for use along with the Citadel Contrast Paint line. Simply, you apply this to a model as a primer coat. The white color acts as an undercoat for applying the Contrast Paint over it; speeding up the process of painting with Games Workshop model paint colors.
As a primer, it works well and provides a very smooth surface for applying overlying model paints. It’s fairly expensive for a primer, but may be valuable for the Contrast Paint Technique of “one thick coat”.
All the pros of regular Citadel Primer plus the added bonus of combining with Citadel Contrast Paint application. The bright color may also be useful for painting traditionally difficult to paint colors like yellow or orange–colors that have generally poor coverage. A brighter base coat primer can help get those color saturations quicker with less effort.
Expensive as a primer. As above, it is an aerosol based spray primer and will require proper ventilation for safe use. A respirator mask (organic vapor P95 rated like this) or spray booth could help when you’re spraying in more enclosed areas.
3. Krylon Ultraflat Primer
The Krylon Ultraflat Primer is a very versatile spray primer that sells for $10. It comes in many different colors. I would recommend neutral gray as a color for most primers when I’m not sure what colors I’d like to paint my miniatures with. The Krylon primer is really good for both plastic and metal miniatures. It is even good on models made of wood or cardboard surfaces (e.g., MDF terrain) as it seals with a solid coat, filling and sealing off porous surfaces.
Because it is an indoor/outdoor primer, it is resilient to many insults from the environment. The Krylon primer can therefore provide a solid undercoat foundation for any miniature painting project. The Ultraflat version of this primer is a key feature because it provides some texture for your acrylic paint to adhere. This adds to the durability of your paint job. There is some limitations though to this primer (see below).
Versatile for many surfaces and resilient to environmental insults. The Ultraflat version provides durability to overlying acrylic paint jobs, by adding surface area to your paint layers. As a primer for miniatures and models, Krylon spray primer is also inexpensive! You can cover a lot of surface area for the cost of this rattle can primer.
Is this the best primer you can use for miniatures? Maybe. As you see below, there are some limitations. In general, I would highly recommend this for larger models and for MDF, laser-cut terrain pieces (which are porous in material nature).
Although this Krylon Primer is durable, versatile for many surfaces, and inexpensive, it sprays on pretty thick. That means you can easily over spray this primer and obscure details on miniatures. It’ll happen fast if you’re not careful. So, if you use this in small miniatures (29-35mm scale) just be aware and spray from a farther distance.
4. Liquitex Neutral Gray Gesso
The Liquitex Neutral Gray Gesso is a gesso compound that sells for $9. Gesso is the perfect alternative to normal primers designed for miniatures. Gesso is fairly hard compound formulated with plaster or some type of glue-like substance. Traditionally, gesso is used on canvas an undercoat before painting (with oils or acrylics), or on stone or ceramic sculptures.
Gesso seals off porous surfaces effectively, and forms a solid foundation to apply paint. In miniature and model painting, gesso is particularly useful for metal or resin because of its durability. Liquitex makes an easy-to-dispense bottle of this Gray colored gesso. Other colors are available.
Great for pewter and resin miniatures. Provides a strong, durable surface. Fairly inexpensive for the amount and how much surface area can be coated. Gesso is versatile. If you’re a traditional painter as well as miniature artist, you can use this for all sorts of projects. Gesso will help make nearly any surface into a paintable-one with most art mediums (oil- or water-based). Liquitex provides this gesso in one of the thinner viscosity forms. Other brands make gesso that is almost paste-like. The thinner viscosity of the Liquitex version of gesso makes it amiable for preserving the fine details on miniatures.
Gesso can often be thick. It is best applied with a brush in layers. This means you need to be careful when you want to preserve details on a miniature. Applying gesso can also be difficult because it is prone to making bubbles in the surface. Gesso application requires some patience as it will take a little longer to dry than other primers. I’ve often left gesso on my models to dry for up to 24 hours.
5. Army Painter Primer
The Army Painter Primer sells for $16. In general, this is similar to the Citadel primer. Army Painter is a modeling company that makes a lot of different products for the miniature hobby. This primer is no exception. It is formulated for all types of miniatures, including those made of plastic and metal.
For most hobbyist, this is the best primer because of its accessibility and easy of use: just shake-the-can, hold back a few inches (6-12″), and spray in quick bursts.
Many colors are available from Army Painter for this primer. However, the black colored primer has the best reviews. The white primer seems to cause some individuals some problems with the quality of the final surface. Some of this is due the environmental conditions in which the primer is sprayed. In general, it is best to use rattle can primers in lower humidity and normal room temperatures.
Easy to find at local hobby shops or game stores. It comes in many colors and functions easily as a spray on primer. It applies thinly when sprayed from a proper distance from the model. In terms of price, it is on par with other competitor products, e.g., Citadel. Overall, it’s a toss up between Army Painter and Citadel branded primers.
As an enamel-based primer it is very useful for a variety of surfaces, forming a durable undercoat layer for subsequent painting. The multiple available colors also make it the best choice for those who want to paint fast, skipping the base coat layers.
As with other aerosol sprays, it requires a ventilated area for safe use. Aerosols aren’t great for the environment. In general, rattle cans have more limited use than compared with polyurethane-based primers, which come in larger volume bottle for less cost.
6. Vallejo Surface Primer
The Vallejo Surface Primer sells for $16 and worth every penny! This is my favorite primer for most miniature and modeling jobs. I use this as both a brush-on primer or thinned out with water (usually) for use in an airbrush.
For the price, a single bottle has lasted me hundreds of models. No kidding. As an airbrush-able primer it sprays really well in thin coats. It dries fast and auto-smooths on the surface of both plastic and pewter miniatures. Because of how thin I’m able to apply this primer, it helps retain details while also smoothing out small imperfections.
In some cases, I’ve used this as a brush-on primer for 3D printed pieces. Using this with a brush allows me to apply thicker coats that are useful for hiding print lines in 3D prints.
Most of the models you see on this site were first primed with Vallejo Surface Primer. Vallejo makes this surface primer in many colors, but as with most primers, I prefer to default to gray.
Works well as both a brush-on or airbrush primer. Auto-smooths as it dries on any surface, including plastic and metal models. I love this stuff. It has easily replaced multiple aerosol spray primer because of how well it coats. A single bottle has lasted me a few months, and I paint a lot!
This Vallejo Surface Primer thins nicely with pure water or Vallejo’s airbrush thinner. Get this primer and give it a try, even if you don’t airbrush it. I’m recommending Gray, but any of the Surface Primer colors are great undercoats.
The cap dispensing system clogs easily. That’s the only problem I have with this primer: the bottle cap. Other than that, I actually can’t find a weakness in the actual primer itself.
7. Tamiya Surface Primer Spray
The Tamiya Surface Primer Spray sells for around $9 and is highly-prized by professional and competitive miniature painters. Tamiya fine surface primer provides a very thin mist that finely coats your models, preserving all the small details. This is especially important for gunpla models, where you need to preserve panel line and rivet details.
Some heavier primers can easily cover these details. As an enamel based primer, it is also durable for plastic and metal miniatures. I’ve recommended the gray color primer as it is the most versatile of the primer colors. But, if you prefer Tamiya makes other colored primers as well, including black and pure white.
Legacy of awesome. This is the key primer for most miniature artists who take the hobby seriously. The quality of the final undercoat with Tamiya surface primer is top-notch. It sticks nicely to any metal or plastic surface. Details stay put and remain easy to resolve even after a few layers of this primer (shake the can vigorously for best results, and spray in a low humid environment).
I should note that the can is small, which is useful for portability. It will fit into most side bags, or model cases with little trouble. If it wasn’t for the fact that I don’t have much ventilated space for using aerosols (I work in a basement), I would definitely be using this primer more.
There aren’t too many cons with Tamiya’s surface primer. It’s well regarded by the miniature and modeling community.
If there’s a knock to this product, it’s the premium price. It’s a small can, and priced at close to the same as the other premium modeling primers out there. Also, as with aerosols, you need a good space to safely spray this an avoid the harmful vapors. The warnings about this are all over the can. But, if you want the best primer for miniatures, you should strongly consider Tamiya’s Surface Primer.
I really like the neutral gray color!
8. Testors Enamel Primer
The Testors Enamel Primer can sells for $9. Testors is a direct competitor of Tamiya’s product. Both are similarly priced with a similar kind of enamel-based formulation for undercoating highly-detailed miniatures and scale models. Everything I said for Tamiya’s primer holds true for Testor’s version.
They are similar on almost every level that I can investigate through online research. For me, Testors is more available in local art supply stores than Tamiya’s product (which is billed as more specialized).
This is a great spray primer. Useful for any surface and is the best primer for plastic, metal, or resin miniatures. As an enamel-based primer, it forms a solid, smooth undercoat in preparation for modeling paint application.
Make sure you shake the can vigorously to mix the primer with the aerosol contents for a proper fine spray. Keep the can more than 6-12 inches away from your working surface of the model. Thin coats should be applied in several layers, waiting for each layer to dry before applying the next. This should only take a few minutes, as this stuff dries fast!
I like the small can. It makes it easy for me to travel with my painting kit and always have primer with me.
It stinks literally. Harmful vapors are not friendly to painting in a basement or enclosed area with poor ventilation. Testors enamel primer is a premium product for modeling, and is priced as such. In my opinion, though, Testors spray primer is a solid product (just make sure you shake it well and spray in a preferably cool, low humidity environment).
9. Badger Airbrush Primer (Stynylrez)
The Badger Airbrush Primer (Stynlrez) is about $8 per primer bottle or $16 for a set of 3 colors (black, gray, and white). It is probably the best deal in terms of volume of primer. But, also note that these are airbrush-ready primers formulated as an acrylic-polyurethane undercoat. This means that they form a tight, non-porous and auto-smoothing layer directly on the unpainted surface of your models.
This is great, and perhaps this is one of the most under-rated, largely ignored primers on the market. And, I’m not sure why except that maybe these primers are not advertised as much as the others and are fairly new on the market.
Badger is a US based company with a great reputation for their line of airbrushes and accessories.
Airbrushing primer is the most cost-effective way to applying primer. These make it easy to apply very thin layers of primer easily. Because these are already thinned for your airbrush, you don’t need to do anything except drop them into your airbrush reservoir cup. For the price, these are also the most inexpensive of the modeling primers available right now.
Given their price and the reputation of the Badger company, I would recommend them as the best airbrush ready primer for miniatures. Because of how thin they are, they could also be useful when applied as as a touch-up primer using a brush.
I’m not a fan of the bottle caps on these Badger paints and primers. The caps tend to clog up, and little drops of liquid dry on the edges of the opening, which makes them hard to close. The Stynlylrez are a somewhat new brand compared to some of the other primers on the list and less well known. So, it may be harder to find more established miniature painters from recommending them.
10. Rust-Oleum Automotive Primer
The Rust-Oleum Automotive Primer sells for around $5 per can, which makes this the cheapest aerosol spray primer on this list. I’ve used this automotive primer to great effect on 3D printed parts and larger terrain pieces made of MDF or plastic.
The advantage of an automotive primer is that it is strong. It cures into a very durable surface over which you can paint confidently. Because it also has a subtle gap-filling component, it also helps smooth out layering imperfections, which are a hallmark of fused-deposition modeling (FDM) 3D prints.
Rust-Oleum primer is also known to protect against environmental exposure, blocking out ambient moisture. This is what gives this primer its anti-rust capability.
For us, this is useful for sealing, protecting, and priming surfaces made of wood, cardboard, or medium density fiber (MDF) pieces. When you paint over this with water-based acrylic paint, you can be sure the paint stays where you put it.
Super cheap aerosol primer. This is the perfect primer for MDF pieces, such as laser-cut terrain pieces. It seals and protects porous surfaces. For miniatures, automotive primer is perfect for smoothing out imperfections and filling tiny gaps in models or 3D prints. It is also possible to use wet or dry sanding methods to further smooth and prepare a surface for paint.
Because it’s a spray can, you can coat very large surfaces quickly and so this is great for larger models. It’ll work on plastic and metal equally well.
My recommendation would be keep the spray can some distance away to ensure you don’t over coat a model and lose details.
You can easily lose details on small models with an automotive primer like this. It’ll easily obscure things like panel lines, rivets, and small folds in sculpts that are in the 28mm scale. I would only suggest the use of this primer on large models. As with any aerosol, there is also the need for good ventilation.