Painting 3D-Printed Models: Primer, Airbrush & Faux Finishes

Quick answer: Painting 3D-printed models involves five stages: cleaning and support removal, sanding through progressive grits (typically from 120–240 up to 400–800), applying a filler primer to hide layer lines, painting with spray cans or an airbrush, and finishing with a protective gloss or matte clear coat. Faux bronze, wood and stone effects are built from a base coat, a transition coat and dry brushing. Typical market rates in Ho Chi Minh City in 2026: single-color painting VND 200,000–500,000 per model (≈ US$8–19), airbrushing VND 600,000–2,000,000 per model (≈ US$23–77); painted models usually take 7–14 days.

A 3D print fresh off the machine still shows layer lines, support marks and a single plastic color. Many customers only realize after ordering that the part “still looks like plastic”, when what they actually need is a display model, a faux-bronze statue or a product sample for photography. Painting is what closes that gap. This article takes a deep dive into painting technique – a key link in our custom 3D model printing service – so you understand why a good paint job takes time and what to prepare when you place an order.

Why Do 3D-Printed Models Need Primer Before Painting?

Primer is the first coat applied to the plastic, and it does three jobs. First, it improves adhesion: PLA, PETG and resin surfaces are fairly slick, and color coats applied directly tend to chip on impact. Second, it fills defects: a filler primer contains fine solids that fill shallow layer lines and sanding scratches. Third, it unifies the base color: a print made from several filament colors or patched with putty becomes an even gray or white base, so the color coats on top come out true.

Metallic paints (gold, silver, chrome) demand an especially smooth primer, because metallics reflect light and reveal every small ripple. A layer line that is almost invisible under a matte finish becomes obvious under a gloss coat.

How Do Surfaces From Different 3D Printing Technologies Compare for Painting?

The amount of sanding and priming depends heavily on the printing technology. The table below shows why, for the same model, a resin print usually needs less prep work than an FDM print.

Technology	Layer thickness	Surface characteristics	Prep work before painting
FDM (PLA, PETG, ABS)	100–300 microns	Visible layer lines, rough support marks	High: multi-grit sanding, putty, 2–3 primer coats
SLA resin	25–100 microns	Smooth, only small support nubs	Low to medium
DLP resin	25–100 microns	Smooth, crisp fine details	Low
SLS / MJF PA12	80–120 microns (SLS)	Grainy powder texture, absorbs paint	Medium: primer needed to seal porosity

Source: CT3D technology specifications 2026; prep effort rated from workshop experience.

For resin parts, the most important step before painting is washing off excess resin and fully UV curing the part. Under-cured resin makes paint tacky, causes peeling or yellowing. This process is covered in detail in our article on resin print post-processing: washing and UV curing.

What Are the Steps in a Professional Painting Workflow for 3D-Printed Models?

Step 1 – Remove supports and clean

Cut supports with flush cutters, leaving small nubs to sand later; avoid ripping them off, which can dent the surface. Wash off plastic dust and skin oils with mild soapy water or isopropyl alcohol (for resin parts) and let the part dry completely. Dust and oil are the most common causes of pinholes and peeling. For more on supports and how to minimize support marks at the printing stage, see what are supports in 3D printing.

Step 2 – Sand through progressive grits

The rule is to go from coarse to fine without skipping too many grits. Coarse paper (around 120–240) knocks down FDM layer lines and support nubs. Medium paper (around 320–400) levels the surface. Fine paper (600–800 and up, wet sanding possible) is used between primer coats and before gloss coats. Sand across the layer lines and avoid pressing hard on sharp edges so you do not round off details. Use sanding sticks and needle files for small features.

Step 3 – Putty and primer

Dents, seams and pinholes are filled with plastic-compatible putty, left to dry and sanded flush. Then filler primer is sprayed in thin, multiple passes. After each primer coat dries, it is lightly sanded with fine paper and inspected under a raking light to reveal remaining lines, with more putty applied as needed. This is the most time-consuming step and determines 70–80% of how good the final finish looks – a common rule of thumb among professional model makers.

Step 4 – Color coats

Single-color models can be painted with spray cans or a spray gun. Multi-color models, gradients and characters with skin, hair and clothing are painted with an airbrush (a mini spray gun). Areas that need crisp color boundaries are masked with dedicated masking tape. The general rule: several thin coats are better than one thick coat, because thick coats run, bury details and take longer to dry.

Step 5 – Details, effects and protective coat

Small details (eyes, lettering, trim) are hand-painted, effects are added (dry brushing, shading washes), and finally a gloss, satin or matte protective clear coat is applied. The clear coat resists scratches and dirt and unifies the sheen across the whole model.

Airbrush vs. Spray Can: What Is the Difference?

Criterion	Spray can (pre-filled aerosol)	Airbrush
Paint control	Low, wide spray pattern	High, adjustable to a fine line
Gradients and shading	Difficult	Smooth and natural
Best for	Single-color models, primer, clear coats	Figures, statues, multi-color models, faux material effects
Labor	Low	High, requires skill
Ho Chi Minh City market rate, 2026	Single color: VND 200,000–500,000 per model (≈ US$8–19)	VND 600,000–2,000,000 per model (≈ US$23–77)

Source: Ho Chi Minh City market rates 2026, indicative only – not a CT3D price list. CT3D quotes based on your file and finish level.

Airbrush paint is thinned to the consistency of milk and sprayed at low pressure. The painter adjusts needle opening and gun distance to get a fine line or a wide band. Because it builds up many thin coats, an airbrushed finish preserves small details such as fabric folds and hair strands that a spray can tends to fill in.

How to Create Faux Bronze, Wood and Stone Effects on 3D Prints

Faux bronze and antique bronze

The base is usually dark brown or black. Next comes a bronze metallic paint, sprayed or brushed on. Then a lighter bronze or gold is dry brushed (load the brush with almost no paint and skim it lightly) onto raised areas – the spots people tend to touch – to mimic bronze that has been polished by handling. For an antique bronze look, add a wash (very thin paint that flows into recesses) in verdigris green in the deep crevices. Finish with a matte or satin clear coat. This technique is widely used for statues, reliefs and trophies.

Faux wood

Start with a light wood base color (beige, tan). The grain is created by dragging dark brown paint in one direction with a dry brush or fan brush, or by applying a transparent glaze and wiping it in streaks. On FDM parts, the printed layer lines themselves can serve as wood grain if the part is oriented sensibly. Finish with matte or satin depending on the wood species being imitated.

Faux stone, terrazzo and concrete

Use textured stone-effect paint or speckle with an airbrush at low pressure, combined with sponge dabbing in several shades of gray and brown. A marble effect is created by painting fine veins with a brush and softening them. A matte clear coat is usually applied to look like real stone.

Chrome and glossy gold

This is the most difficult effect. The base must be a mirror-like gloss black, completely dust-free. Every speck of dust and every layer line will show. If a customer needs the look and feel of real metal, CT3D will also advise on plating; see our 3D printing, plating and painting service.

Which Paint Should You Use on 3D-Printed Plastic?

Paint type	Advantages	Limitations	Use when
Water-based acrylic	Low odor, easy to thin, cleans up with water	Poor scratch resistance without a clear coat	Airbrushing figures, hand-painted details
Solvent-based paint (lacquer, spray cans)	Good adhesion, fast drying, durable	Strong odor, needs ventilation	Primer, base coats, single-color models
2K polyurethane (PU) paint	Very durable, deep gloss	Must be mixed at the right ratio, long drying time	Long-term display models, appearance prototypes
Metallic and pearlescent paint	Metal effects	Requires a very smooth base	Trophies, faux-bronze statues, decorative details

Source: general paint material knowledge; recommendations based on CT3D experience.

Note: strong solvents can soften or craze the surface of some plastics. Always test-spray on a sample or a hidden area first. ABS can be smoothed with acetone vapor before painting, but this rounds edges and is not suitable for models with sharp details.

Common Problems When Painting 3D-Printed Models and How to Fix Them

Problem	Cause	Fix
Paint peeling in patches	Oil or dust on the surface; no primer; under-cured resin	Clean, fully UV cure, scuff-sand lightly, use primer
Layer lines still visible	Not enough sanding grits, primer too thin	Multiple coats of filler primer, sand between coats, inspect under raking light
Runs and drips	Spraying too thick, too close, in one coat	Spray several thin coats, keep your distance, sand out drips and respray
Orange peel texture	Paint too thick, wrong pressure, solvent flashing too fast	Thin correctly, adjust pressure, sand smooth and recoat
Cloudy white surface (blushing)	High humidity when spraying solvent-based paint	Paint in a dry area, avoid rainy, humid days
Fine details filled in	Primer and color coats too thick	Use an airbrush, reduce the number of coats on detailed areas

Source: finishing experience at the CT3D workshop.

How Are Painting Time and Cost Calculated?

Painting time is not just spraying time; it also includes drying time between coats. A model with 2–3 primer coats, 2–3 colors and a clear coat can take several days even if the total labor hours are modest. That is why the market typically quotes 7–14 days for painted models, compared with 1–3 days for unpainted prints from a ready-to-print file.

Painting cost depends on surface area, the number of colors and masked areas, the level of detail (hand-painted eyes, lettering), the type of effect (faux bronze and chrome take more work than a single matte color) and the printing technology (FDM parts need more sanding than resin). At CT3D, post-processing – sanding, painting and plating – is priced separately from printing. Send us your file and a description of the colors you want, and our engineers will quote each item. For an overview of finishing steps beyond painting, see 3D print post-processing basics.

Checklist for Requesting Model Painting

• The 3D file, or photos of the printed part (if you printed it yourself and want it painted).
• A color reference: color codes, sample photos, or photos of the real product to be replicated.
• The desired effect: matte, gloss, metallic, faux bronze, faux wood, faux stone.
• Intended use: indoor display, outdoor, product photography, frequent handling.
• Quantity and deadline.

Where Painting Is Used Across Model Types

Painting is the final step for most of the models CT3D produces: character figures, religious statues, architectural models, product display models and trophies. Published projects such as the restoration of the Our Lady of La Vang statue, a large reclining Buddha, a 1 m tall SLA-printed Catholic statue and the Ca Mau shrimp model all required painting to reproduce color and material. If you are making trophies, see custom 3D trophies; for product launch samples, see appearance prototypes and display models. When you need to replicate many painted models, the step before that is making a silicone mold from a 3D print.

An overview of model types, materials and pricing is available in our pillar article on custom 3D model printing.

Frequently Asked Questions

Can you paint a 3D-printed model directly?

You can, but the paint chips easily and layer lines show through. Clean, sand and prime first so the paint adheres well and the surface is smooth.

How long does it take to paint a 3D-printed model?

It depends on the number of coats and colors. At typical market lead times, prints with a painted finish take 7–14 days, mostly due to drying time between coats.

How much does airbrushing cost?

Ho Chi Minh City market rates in 2026 are about VND 600,000–2,000,000 per model (≈ US$23–77), and single-color painting about VND 200,000–500,000 per model (≈ US$8–19). These are indicative figures, not CT3D prices; CT3D quotes based on your file.

Do resin prints need primer?

Yes, ideally. Resin is smoother than FDM but still needs thorough washing, full UV curing and a thin primer coat so the paint bonds well and does not yellow.

How do you make a plastic model look like real bronze?

Use a dark base, apply bronze metallic paint, dry brush a lighter tone onto raised areas, add a verdigris wash in the recesses for an antique look, then apply a matte clear coat. If you need the feel of real metal, consider plating.

Real Footage From the CT3D Workshop

Watch the video Custom SLA 3D Printing and Painting by CT3D to get a clearer picture of the process and product quality. More videos are available on our YouTube channel Che Tao Vlog – CT3D.

Contact CT3D – Send Your File, Get a Fast Quote

Whether you have a 3D file, a 2D drawing, photos or just an idea, you can send it to CT3D. Our engineers will check the file, recommend the right technology and material, and send you a quote with a lead time.

• Email: [email protected] – [email protected]
• Hotline / Zalo: +84 975 008 728 (Mr. Thai) – +84 985 936 728 (Mr. Dang), or use our contact form
• Headquarters: Binh Duong.
• Workshops in Ho Chi Minh City: Linh Trung (Thu Duc), Tam Binh (Thu Duc), former District 6.
• Other workshops and drop-off points: Can Tho, Da Nang, Bien Hoa, Ba Ria – Vung Tau, Hanoi, Hai Duong, Hai Phong. Nationwide delivery across Vietnam.
• Website: ct3dgroup.com – in3d.edu.vn

CT3D – 3D design & prototyping: 3D printing, 3D scanning, reverse engineering, silicone mold making, finishing and painting, CNC machining, composite fabrication, plus 3D printers and 3D printing materials.