How to Use Acrylic Paint Primers for Tabletop Gaming, Miniatures, and Models
Make Your Miniatures, Models & Terrain Paint-Ready
What is Primer and Why It Matters?
Priming is the first and most important step in painting models. A good primer creates a surface that helps paint adhere better, go on smoother, and stay durable over time. Without it, acrylic paint may bead up, peel off, or look blotchy — especially on plastic or metal.
Benefits of Using Acrylic Primers
- Improved Adhesion – Ensures paint sticks to plastic, resin, metal, or wood.
- Enhanced Color Vibrancy – A uniform basecoat boosts color consistency.
- Surface Smoothing – Fills micro scratches and minor imperfections.
- Prevents Paint Flaking or Peeling – Extends the life of your paint job.
- Helps Paint Flow Evenly – Especially useful with fine detail models.
How to Use Acrylic Primers
Step-by-Step Instructions
- Surface Preparation
- Clean your model thoroughly (soap and warm water or Micro-Mark Cleaner).
- Let dry completely.
- Lightly sand rough areas if needed.
- Choose Your Primer Color
- White Primer (29398): Best for bright, saturated colors.
- Black Primer (29399): Ideal for dark tones or speed painting.
- Gray Primer (29400): Balanced choice for neutral tones.
- Application Methods
- Brush-On: Thin slightly with Micro-Mark Thinner (29294) or other thinner if needed.
- Airbrush: Thin 1:1 with Micro-Mark Airbrush Thinner (29312). Spray at 20–25 PSI in thin coats.
- Apply Thin, Even Coats
- Let each coat dry before adding another (about 15–30 minutes).
- Two light coats are better than one heavy coat.
- Cure Time
- Allow to dry fully before painting (2 hours minimum; overnight preferred for best adhesion).
Common Questions
Q: Do I really need primer for plastic?
Yes. Acrylic paint does not bond well to smooth plastic. Primers create a micro-textured surface that grips the paint.
Q: Can I skip primer for metal?
No. Metal is even harder for acrylics to adhere to without a primer layer. Always prime metal models.
Q: Can I use this primer under enamel or lacquer paints?
Yes, but do a test first — some strong solvents may affect the acrylic base. For acrylic paints, it’s ideal.
Pro Tips
- Use Gray Primer for general-purpose miniatures to keep color balance predictable.
- White Primer makes fluorescent or pastel colors pop more.
- Black Primer is great for fast workflows like drybrushing or contrast-style paints.
- Use a retarder (29268) in humid conditions to prevent brush streaking.
Frequently Asked Questions from Beginners to Experts
Beginner-Level FAQs
1. What is a primer and why do I need it?
A primer is a preparatory coating applied before painting to help paint adhere better to surfaces. It ensures smoother application, better durability, and more vibrant colors.
2. Can I paint my model without using primer?
Technically yes, but it’s not recommended. Paint may bead, peel, or chip easily without a primer, especially on plastic or metal.
3. What’s the difference between primer and paint?
Primer is formulated to bond to surfaces and provide a grip for paint. Paint provides color and finish but doesn’t adhere well without a primer underneath.
4. Which color primer should I choose: white, gray, or black?
- White for bright or pastel colors.
- Gray for neutral or versatile projects.
- Black for dark tones or pre-shading techniques like zenithal priming.
5. How do I apply acrylic primer with a brush?
Use a clean synthetic brush and apply thin, even coats. Avoid overbrushing and let each layer dry before applying another.
6. Can I use primer straight from the bottle?
Yes for brushing, but thin with Micro-Mark Thinner for airbrush use.
7. Do I need to thin a primer before using it?
Only for airbrushing. Use a 1:1 ratio with Micro-Mark Airbrush Thinner (29312) for smooth spray application. Or you can purchase Micro-Mark Airbrush Primers.
8. How long does primer take to dry?
Touch dry in 15–30 minutes. Fully cured in 1–2 hours. Allow 12+ hours for best results before heavy handling or masking.
9. Can I use a hairdryer to speed up drying time?
Yes, use on a low, cool setting and keep airflow indirect to avoid disturbing the primer layer.
10. Do I need to sand my model before priming?
Only if the surface is rough or has mold lines. Light sanding (400–600 grit) improves adhesion.
11. Is this primer safe to use indoors?
Yes. Acrylic primers are water-based and non-toxic. Use in a well-ventilated area.
12. Can I use acrylic primers on plastic only, or will it work on metal and resin too?
It works on plastic, resin, metal, and even wood. Always clean surfaces before priming.
13. Will primer cover up mistakes or seams on the model?
It may reduce the appearance of very fine scratches, but it's not a filler. Use putty or sanding for gaps and large imperfections. You can use Micro-Mark Textures value package Item # 29440. The Sand Texture is a little thicker than the others.
14. How many coats of primer should I apply?
Two light coats are typically enough. Avoid heavy layers to preserve fine details.
15. What should I do if the primer looks streaky or blotchy?
Let it dry, then lightly sand and reapply a thinned coat. Uneven application often comes from too much primer or using the wrong brush.
Intermediate-Level FAQs
1. What PSI should I use when using acrylic primers with an airbrush?
Use 20–25 PSI for consistent, even coverage.
2. What thinner should I use for airbrushing acrylic primers?
Use Micro-Mark Airbrush Thinner (29312) or distilled water with a few drops of Flow Improver (29313).
3. Is Micro-Mark primers compatible with other brands of acrylic paint? Are other brands compatible a variety of other brands of mediums?
Yes. It Micro-Mark works with Vallejo, The Army Painter, Citadel, and most hobby acrylics. Not all brands of primers are compatible with other brand thinners. Need to test before using.
4. How can I tell when the primer coat is dry enough for paint?
The surface should feel dry to the touch, not tacky. Wait at least 1–2 hours before painting for best results.
5. Should I lightly sand the primer layer before painting?
Optional, but light sanding (1000–1500 grit) can improve paint flow if surface texture feels rough.
6. Can I use acrylics primer on 3D printed models?
Yes for most acrylic primer brands including Micro-Mark’s primers. It’s great for smoothing and prepping PLA, resin, or ABS prints. Clean and degrease thoroughly first.
7. Does the primer obscure fine details on miniatures?
Not if applied in thin coats. Avoid heavy brushing or over-spraying.
8. Can I use this primer as a base for metallic paints or washes?
Yes. A smooth gray or black primer base works especially well for metallics and weathering techniques.
9. How should I clean my brush or airbrush after using an acrylic primer?
Use Micro-Mark Cleaner (29295), other acrylic paint cleaners, or warm water immediately after use. Clean as soon as possible. Don’t let the primer dry inside your equipment.
10. What’s the shelf life of acrylic primers?
Typically 2–3 years if sealed tightly and stored in a cool, dry place.
11. What’s the difference between Micro-Mark primer and Vallejo or The Army Painter primers?
Micro-Mark primers are formulated for direct-to-consumer flexibility — brush or airbrush out of the bottle — with strong adhesion and lower odor than most competitors. Micro-Mark primers are premium quality but less expensive and you get more per bottle.
12. Will the primer react badly with enamel topcoats?
Usually no, but test first. Heavy solvent-based paints can soften acrylic primer if applied too wet.
13. Can I apply decals over the primer layer directly?
Not recommended. Apply a gloss or clear coat first for a smooth surface that prevents silvering.
14. What’s the best lighting to use to check primer coverage?
Use cool white or daylight LED lighting at 45–90° angle to highlight surface texture and spot missed areas.
15. What humidity/temperature range is best for priming indoors?
60–75°F and 40–60% humidity. Avoid priming in extreme cold, heat, or moisture.
Expert-Level FAQs
1. What’s the resin binder or polymer base in Micro-Mark acrylic primers?
It uses an acrylic polymer emulsion similar to artist-quality paints, engineered for mechanical adhesion and flexibility.
2. How does Micro-Mark primer adhere chemically to polystyrene or resin?
It relies on mechanical adhesion — forming a micro-tooth structure on the surface — rather than chemically bonding like solvent-based primers.
3. How does primer thickness affect subsequent paint layering or modulation techniques?
A thick primer can fill details and alter shading. Aim for 15–20 microns or less per layer for zenithal or modulation painting.
4. Can I wet sand Micro-Mark primer after application?
Yes, once fully cured (overnight). Use 1000–2000 grit wet/dry sandpaper. Not all acrylic primers can we wet sanded.
5. What is the ideal surface profile (microns) for optimal paint adhesion?
A surface roughness of 1–2 microns (achieved via primer + light sanding) is ideal for acrylics.
6. How does primer color affect final tone in zenithal highlighting?
White reflects light, boosting brightness. Black enhances shadows. Gray balances both. Use all three for layered priming.
7. Can I mix pigments or tints directly into the primer?
Not recommended unless you test. Adding pigments may disrupt bonding or flow characteristics.
8. Can this primer be tinted for use as a colored basecoat?
Yes, some acrylic primers can. Micro-Mark primers can be tinted with Micro-Mark paints or a small amount of high-flow acrylic pigment. Thin accordingly.
9. What’s the chemical resistance of Micro-Mark primer when exposed to lacquer washes or oil-based weathering?
It resists mild solvents but may soften with heavy lacquer thinners. Apply a protective clear coat first if using aggressive chemicals. Micro-Mark Acrylic Clear Coat Item # 29385
10. What is the failure mode if this primer is applied too thick or too thin?
Too thick: cracking, obscured details, peeling.
Too thin: patchy coverage, poor adhesion, flaking.
11. Can this primer be baked (cured) under heat lamps or low-temp ovens to harden faster?
A warm (90–100°F) drying box or heat lamp can help, but avoid high temps that soften plastic models. Another solution for a faster cure is Micro-Mark’s Dr. Dry Booth for time-saving drying precision Item # 88043
12. What is the particle size of the pigment in the primer, and how does it affect detail preservation?
Micro-Mark primers use ultra-fine pigments (less than 10 microns) to preserve model detail and ensure even coverage.
13. How does Micro-Mark primer compare in mechanical adhesion vs. Vallejo Surface Primer or Tamiya Fine Primer?
Comparable or better on plastic and resin. Tamiya (solvent-based) bonds differently; Micro-Mark excels for safe indoor use and airbrush control.
14. What cleaning solutions are compatible with Micro-Mark primer residue in airbrushes (e.g., acetone vs. ammonia-based)?
Use Micro-Mark Cleaner, water, or mild ammonia solution. Avoid acetone—it may damage seals and plastic components.
