Table of Contents
Do you want to learn how to paint 3D print PLA? Please see our simple guide to paint 3D print PLA for more information. ABS is also an option.
Paint 3D Print PLA
Begin with a Solid Model
Because final prints are rarely showroom-ready, you may need to rely on some post-processing to get a model to the final mile.
This guide walks you through the basics of painting PLA and ABS 3D prints, from smoothing to the actual painting process, with some helpful hints thrown in for good measure. You might prefer spray painting over using a brush or airbrush in this case because it is less time-consuming and less expensive, as will be explained later.
Let’s get creative now!
Paint 3D Print PLA
Which Paint Should You Use?
Paints are classified according to the solvent they use. Oils, enamels, lacquers, and acrylics are the most common, and they all work well with ABS and PLA. As a beginner, stick to acrylic paints because they dry quickly, and you can clean with water.
It would be best if you usually chose between using an airbrush, a brush, or canned spray paint. While a brush is less expensive than the other options, applying an even coat of paint can be challenging. It leaves noticeable blobs in some areas and reveals the underlying color in others. On the other hand, airbrushes are expensive and have a steep learning curve.
Spray paints are the only option, as they strike a good balance between cost and ease of use.
Paint 3D Print PLA
Smoothing
Pre-sanding
The first stage is pre-sanding, which entails trimming rough print features like support stubs before sanding.
In this stage, you can use some of the following:
The most important thing is to eliminate any protrusions and clean up the print. You can peel off supports with your hands or with a knife. It makes no difference as long as there are no bumps or protrusions in the final product.
Sanding
Start with 120-grit sandpaper and gradually increase the grit. The finer the sandpaper, the higher the grit number. To avoid visible scratches, work in circular motions and focus on the sides while avoiding the edges, corners, and other fine details. After all, 120 grit is too coarse for small items.
Sanding smooths out deformities and, depending on the size of the print, can take a long time. Sand the support marks and make sure any filing or tooling marks are gone.
Progress through the grits depending on your print, but start using water once you’ve reached 200 grit. Water avoids clogging and produces a more appealing result.
Feel the print’s surface at intervals while sanding to get an idea of how smooth it is. Once the smoothness is to your liking, wash away any trapped dust with a brush and water. Naturally, you’ll want to wait for the print to dry before proceeding.
Paint 3D Print PLA
Priming
Priming transforms your 3D print into a professional product by creating a flawless final surface and simplifies the painting process. Priming is required because paints will never hide flaws, especially when making a near-perfect object.
Choose a primer that will work with your plastic. We prefer to use a spray-on primer to coat the entire surface with an even coat quickly. Brush-on primers, on the other hand, are better for fine touch-ups.
Steps in the Application Process
Mix the primer (do not shake): Swirl (not shake) the spray primer in a circular motion; the pigment should dissolve into the solvent for a few minutes. Swirl until the mixing ball (also known as a “pea”) inside the can starts to roll. Shaking the coat will cause bubbles to form when you spray it.
The first coat:
- Hold the spray 10-12 inches away from the part and use short, rapid strokes to apply it.
- As you spray, rotate the part.
- Make sure the spray doesn’t pool on the part.
To make the spraying process more manageable, you’ll want to mount your model on makeshift support.
Examine the first coat: Check for any areas that require additional sanding or filing. You may need to alternate sanding and primer spraying until you achieve a smooth surface. If you need to sand, you’ll have to clean up the dust before repainting.
Rebuild blemishes with spot putty if necessary. You can use a scraper to apply it. Fill in the gaps on the surface, but be careful not to lose detail. After your print is completely covered, wait 15 minutes for it to cure before sanding.
Spray the final coat: Apply another layer with rapid strokes and a light touch. A thick coat will fill in the fine details, so avoid it. Sweeping across the part in quick bursts is the best technique. This method prevents paint from adhering to the surface and dripping.
Allow your primer to dry completely before applying additional layers. For a clean surface finish, two layers are usually sufficient.
Because we’re only using the first two coats to improve adhesion for the subsequent layers, they should be very light. However, a primer is sufficient to improve the surface finish and aesthetics of the printed part, some people opt to use it instead of any other painting.
Your part is now ready to paint after the final primer coat has been applied.
Paint 3D Print PLA
Painting
You should have a mental image of the finish you want to achieve at this point. Painting is similar to priming in that it is a two-step process.
You’ll require the following items:
Tape for painting: Painter’s tape adheres to surfaces firmly but quickly peels away. This tape will cover some areas of the printed parts to keep seeping through the paint. To force the tape into the creases of your model, use a hard object like a credit card.
We highly recommend Tamiya spray paints because they come in various colors and finishes and are compatible with plastic.
Steps in the Application Process
Apply the first coats: Move quickly while holding the nozzle near the rotating model. To avoid sagging, start with two light coats and finish with three or four wet passes, pausing 5 to 10 minutes between each. You can buff and polish the paint surface to maintain a smooth surface that will look glossy under the clear coat if you want to refine it further, but this is optional.
Apply the topcoats: To preserve details, mask the relevant areas before applying the topcoats. Overcoats are like layers on top of the previous coats. If the topcoat is thinner, the first and second coats will show more, but in between applications, let the paint sit for a few minutes to see if the color is saturated enough.
(Optional) Finish with a clear coat to “seal” the painted model and protect the paint surface while achieving the desired sheen. Wait about 10 minutes between applications and apply the clear coat in one or two thin and even layers. You finish the painting process at this point, but if you want a super glossy finish, you can polish it even more with wax or a fine polishing compound.
Allow the paint to dry overnight before cleaning the part with a tack cloth the next day.
There are a few things to keep in mind:
Masking: Remove the tape as soon as possible after masking to ensure clean, sharp edges between colors. You don’t need to coat the mask because the tape is supposed to keep seeping through any paint.
The first coat: When you want rich color, a first coat is recommended because it blocks the neutral color of your primer. In general, light colors benefit from the first coat of white, while darker tones benefit from a coat of black.
Topcoats: Topcoats are optional, but they will allow you to create gradients of rich color blends if you use a contrasting color. However, use a light hand with the topcoat if you want the first and second coats to show through.
Layering: The most intricate parts are painted in multiple layers, beginning with the first coat, the painted model’s foundation. You can make a few adjustments to highlight details, create reflections, or give your image a weathered look.
Paint 3D Print PLA
Important Spray Painting Recommendations
Here are some general tips to help you improve the above steps:
- Paint in a confined space with no drafts or wind. Remember that even the tiniest air movement can cause the paint particles to change direction.
- If you want the paint to spread evenly, do all of your spray painting in one sitting.
- Items are near the spraying zone must be covered because specks of paint can get on them. Alternatively, you can spray the piece while holding it inside a cardboard box. Covers protect the surrounding area from paint and keep the painted item dust-free while it dries.
- Spraying too close to your print will result in noticeable drips.
- Multiple coats are preferable to a single coat, but each skin should be light.
- One trick is to use an existing hole to mount your model on a dowel. So you could move around more easily while spraying and access all of the nooks and crannies without leaving fingerprints.
- Because your painted part will need time to dry, figure out where it will go. It’s not a good idea to move the model while it’s drying.
- Spray paints are hazardous. They’re toxic and flammable, and inhaling them can be dangerous. It’s best to dress appropriately, wear rubber gloves, and use a respirator to be safe.
The painting should not be an afterthought; you should consider it from the beginning of the design process. Because you can achieve so many different things, it’s best to experiment to find what works best for you.
