How to paint 3D prints
Painting a 3D print is a surface-preparation and coating workflow: remove supports, smooth only the defects that matter, clean away residue, test compatible primer and paint on scrap, then build the finish in thin coats. The material and coating makers' ventilation, protective-equipment, recoat, and cure instructions control the job.
Paint a 3D print in eight steps
- Identify the printed material and the finish the part needs.
- Remove supports and trim rough edges without gouging the model.
- Sand visible layer lines or support marks that would show through paint.
- Clean away dust and let the part dry completely.
- Test the chosen primer and paint together on scrap or a hidden area.
- Apply a compatible primer in controlled coats and inspect the surface.
- Correct remaining scratches, then build color in thin coats.
- Let the coating cure as directed before assembly, handling, or optional clear coat.
Tools and materials
- Flush cutters and a deburring tool for controlled support cleanup.
- A range of appropriate abrasives, used only where the finish requires smoothing.
- A brush, lint-free cloth, and cleaning method compatible with the printed material.
- Primer that identifies compatibility with the plastic or resin.
- Paint selected for the material, detail method, environment, and final handling.
- Masking materials and a holder that keep fingers off wet surfaces.
- Ventilation and protective equipment specified by the coating and material makers.
Paint methods compared
| Method | Good starting use | Control to practice | Common mistake |
|---|---|---|---|
| Brush | Small details, accents, and controlled touch-up | Thin paint and deliberate strokes | Trying to hide deep layer lines with a thick coat |
| Aerosol | Primer and even base color on suitable parts | Distance, overlap, ventilation, and recoat timing | Flooding corners or spraying an incompatible plastic |
| Airbrush | Gradients, small-area control, and thin color layers | Reduction, pressure, distance, and cleaning | Using paint or solvent the equipment or part does not support |
| Dry brushing or wash | Raised detail or recessed texture after a base coat | Small tests and gradual contrast | Adding effects before the base layer has cured |
Prepare FDM and resin prints differently
For FDM, support marks and layer lines usually control the visible preparation. For resin, complete the exact material's washing, full drying, required post-curing, support removal, and sanding sequence before optional coating. Uncured resin and contaminated wash liquid remain part of a controlled dirty workflow.
Primer reveals problems; it does not erase them
A light primer coat can expose scratches, seams, and uncleaned support marks. Let it dry under its instructions, correct the surface, and re-prime only where needed. Heavy primer can soften detail without fixing the geometry underneath.
Finish for the real use
A display model, costume prop, flexible part, outdoor sign, and handled fixture need different coating systems. Flexible TPU and low-surface-energy plastics can need specialized preparation. Paint does not make a printed material food-safe, skin-safe, weatherproof, heat-resistant, or structurally stronger unless the complete finished system is documented for that use.
Choose the base material first with the PLA, PETG, and TPU guide, or review the resin post-processing workflow before coating a resin part.