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Basic craft supplies will not suffice when it comes to finishing 3D prints. This how to paint 3d printed guide will help you step up your game.
Prints like an Oil Painting
Despite the multi-material extruders’ capabilities and the vast array of filament colors available, you may find yourself wanting to paint some of your 3D prints. The most common reason for doing so is to improve the print quality, especially if you have an FDM 3D printer that uses layers of filament to build the model. A surface of characteristic lines along the Z-axis is created by the way a part is printed.
The small cavities between the layers can be sanded down, filled in, or both to achieve a smoother surface when finishing your model. Painting the model will help to smooth the surface texture while also protecting it from the elements.
In this article, we’ll go over the various methods for painting your 3D print before (hopefully) answering all of your burning questions about painting and how to do it properly. Continue reading to learn how to make perfect paint prints!
How To Paint 3D Printed Objects (PLA, PETG, ABS, Nylon)
Paint’s Best Friend is Primer
Paint adhesion is improved by priming a model. Using primer with any painting method (except dyeing nylon) is a good idea.
Primary Choices
It’s usually easiest to get good results with spray primers: Tamiya and Rust-Oleum are two well-known brands.
Technique
- Your model should be cleaned and sanded.
- Apply thin, even coats of primer.
- To achieve a smooth surface, sand after the first and last coats.
- Allow each coat to dry according to the primer’s directions.
How To Paint 3D Printed Objects (PLA, PETG, ABS, Nylon)
Method 1: Paint Brushing.
It’s simple to achieve a hand-painted look by painting your model with a paintbrush. This method works best with PLA, ABS, and PETG models.
Tips & Tricks
Select a good brush that is stiff enough to handle the viscosity of the paint you want to use. The right paintbrush will help you get the paint where you want it on the surface without dragging it too much.
Try out a few different paintbrushes first, as it’s easier to achieve a good result with a brush you’re familiar with. To find what works best for you, try a variety of bristle types and handle shapes. We frequently use only one or two different flat brushes.
As soon as the paint begins to dry, stop painting to clean the brush. You should, of course, clean it after each use. You don’t want any paint to dry on the bristles in any way.
After cleaning your brush, always store it by resting it on the handle rather than the bristles.
Paint Choices
When it comes to painting with a paintbrush, acrylic paints are the way to go.
Technique
- Your model should be cleaned and sanded.
- Apply thin, even coats of paint.
- Allow for drying time between coats.
- Watch this Formlabs video for a complete brush painting tutorial.
How To Paint 3D Printed Objects (PLA, PETG, ABS, Nylon)
Method 2: Aerosols
Spray paints can produce good results and a more uniform appearance. This method is best for PLA, ABS, and PETG models printed with a paintbrush.
Tips & Tricks
Different brands’ spray cans have different nozzles, so pay attention to the differences you prefer. Before using, give the can a good shake for as long as the manufacturer recommends. You want the paint to be as evenly distributed as possible.
Keep the nozzle free of debris. This is usually accomplished by spraying some upside-down at the end of each session.
Store the can away from open flames and in a cool location. (You don’t want it to get too hot because it’s a pressurized container!)
Paint Choices
When looking for spray paint, you’ll notice that there are numerous options. Be aware of the differences between the RAL, CMYK, and RGB color systems if you’re trying to match a specific color.
Technique
- Your model should be cleaned and sanded.
- Begin spraying with the stream a few inches outside the edge of the object you want to paint.
- Spray the paint in slow, even strokes on the surface you want to paint.
- Stop spraying slightly outside the thing you want to paint.
- Allow for drying time between coats.
How To Paint 3D Printed Objects (PLA, PETG, ABS, Nylon)
Method 3: Dyeing (Nylon Only)
We recommend dyeing models printed with nylon filament rather than getting paint to stick to the surface.
It’s worth noting that this won’t work on any other materials. PLA is hygroscopic, which means it will absorb some water from its surroundings, but it cannot be dyed. ABS and PETG have no place here – this is a nylon-only area.
Tips & Tricks
When 3D printing nylon, use a translucent or white nylon filament to let the dyed color show through as much as possible. It is also possible to dye darker nylon filaments, but the color will be much less pronounced.
Always read the dye’s manufacturer’s instructions before using it.
Because nylon is highly hygroscopic, it absorbs water even when exposed to the elements. That’s why, before 3D printing, you should always dry your nylon filament. Instead of dyeing the unprinted material, we recommend dyeing the finished model.
You might want to dye some test prints before the actual print job to make sure you get the right color.
Dye Choices
You can choose from a variety of dye brands, but MatterHackers recommends Rit DyeMore. You should be fine as long as the dye is made for synthetic fabrics like nylon.
Technique
- Make sure your model is clean. If you sand your model, keep in mind that dyeing will not cover any scratches or marks on the surface. Even after dying, everything will be visible.
- In a pot, combine the dye with the water and heat it.
- Keep an eye on the temperature of the dye with a thermometer. Stick to the manufacturer’s instructions, but keep the temperature below the heat deflection temperature of your filament.
- Attach a weight to your 3D print and place it in the dye pot.
- Rinse thoroughly in cool water after dyeing.
How To Paint 3D Printed Objects (PLA, PETG, ABS, Nylon)
FAQ: What Makes Paint Stick?
The difference in surface energy between the liquid and the solid is probably the most essential factor in making the paint, or any liquid substance, stick to a solid surface. (Dynes, or dynes per square centimeter, are a unit of measurement for surface tension.) The one with the greatest surface tension is always the winner.
For good adhesion, the surface tension of the paint must be at least 10 units lower than the surface tension of the solid. That means we have a liquid with a high ability to wet the stable, which is what we’re looking for.
Creative Tactic
Take note of the shape a drop of liquid takes on a solid surface to get an idea of how well it wets the surface you want to paint:
Apply a drop of paint or liquid to the area that needs to be finished.
If the liquid forms a ball, it has too much surface tension to wet the object effectively. The solid will be unable to “pull” the liquid onto itself.
The wetting is better if the liquid spreads out on the surface, forming something resembling a lens.
How To Paint 3D Printed Objects (PLA, PETG, ABS, Nylon)
FAQ: Can You Paint All Plastics?
It’s simple to paint FDM 3D printed models made of PLA and ABS.
PETG, on the other hand, maybe more difficult to paint with a long-lasting finish, but the same preparations apply as with PLA and ABS. If you really want the color to stay, we recommend printing your PETG model in the color you want it to be and then leaving it alone.
When it comes to FDM 3D printed nylon, getting liquids like paint to stick to the surface becomes much more difficult. Painting on nylon is possible, but it necessitates heat treatment to increase the surface tension and allow the paint to wet. This is frequently done with an open flame or plasma, which is not something you want to do at home. We believe that dyeing nylon, as previously described, is far superior.
