How to Paint 3D Prints? [Step-by-Step Guide]

Three Dimensional Printing, commonly called 3D Printing, can create tangible products from a digital design by printing and fusing small layers of material. This technology enables extraordinary personalization and a major industrial revolution. 

Painting is the most effective method for giving your 3D-printed creations a completed, professional appearance.  The paint conceals flaws and also serves as a protective coating, making the 3D image more resistant to deterioration from external elements such as UV rays and moisture.

This article will provide steps and tips for creating amazing 3D-printed products. To learn more about 3D Printing, the materials, and the steps involved in painting, you can read the following.

Seven Steps in Painting 3D Prints

The best way to make your designs look polished and visually appealing is through painting. To begin painting, you don't just start rubbing or spraying it onto the print after 3D printing. You need to follow vital steps before, during, and after painting to achieve professional results

Read on for a detailed step-by-step process of how to paint 3D-printed models, along with helpful tips for finishing a quality project.

Step 1: Secure Materials Needed for Printing

Choosing a material for 3D printing takes work. It often requires balancing multiple attributes to accomplish the desired result. 

Whether you are creating a prototype for a product design, a home decoration, or a functional part, painting is a reliable method to add protection, hide imperfections and enhance the appearance of your 3D prints. 

Here are some of the essential materials used in painting 3D prints:

Types of Paint Suitable for 3D Prints

Before preparing your 3D print for painting, let's examine which paints are compatible with thermoplastics such as PLA. PLA is one of the thermoplastic filaments that are simplest to paint. With proper surface preparation and priming, most paint varieties will adhere to the material's surface. 

Although many pigments are compatible with PLA, various options are available to you in terms of paint material and application technique. 

The following are examples of standard 3D printing paints that you can use.

1. Acrylic 

The most common type of paint used for 3D printing. It is also the most user-friendly and cost-effective type of paint. It adheres well to a variety of surfaces and has excellent coverage.

2. Oil-based

It can produce prints with vibrant colors and incredibly realistic details. Oil-based pigments do not dissolve in water, requiring chemical cleaning and removal. Oil paints require several days to cure, making them ideal for traditional techniques requiring extensive blending. 

3. Spray Paint

Spray paint is the finest option when painting a large 3D print or when only one or two colors are required. Spray painting applies coats swiftly and evenly, so it's ideal for projects that require speed and efficiency. 2-in-1 formulations paint and prime an object simultaneously. 

4. Enamel Paints

When cured, enamel pigments are among the most resilient. Like Acrylics, they require at least 24 hours to dry, and it is preferable to allow them to dry for longer to achieve optimal strength or durability. 

5. Lacquer

Lacquer is typically a clear topcoat applied over a painted model to seal and protect the paint and create a hard, durable layer. Usually, it can have either a glossy or matte finish. 

Now that you know what kinds of paints work best with 3D printing, we'll go into detail about the primers you should use.

Recommended Primers for 3D Printing

Priming is an essential process before painting 3D prints. It provides a uniform exterior for the paint to adhere to. Choosing a primer and color from the same brand will produce the best results for your model. 

Here are some recommended primers that you can select to transform your print into a dazzling, display-ready product.

• Vallejo Surface Primer - All-purpose brush-on or airbrush primer.

• Rust-Oleum Primer and Filler - Great for larger models, fill, and smooths build lines.

• Testors Enamel Primer - Recommended aerosol spray primer.

Other Materials for Painting

Aside from the paint and primers, here are some materials for 3D printing.

• A paintbrush: If you use liquid or solid paint, you will need a paintbrush to apply it.
• A damp cloth: After cleaning the print, you will use this to wipe the surface.
• Masking tape: This is useful for protecting parts of 3D prints you don't want painting, so the paint only goes where it's meant to.
• Sandpaper: For smoothing out any rough edges on 3D prints.
• Water or Isopropyl alcohol: For cleaning the print.
• Pliers or a knife: Remove supports and other unwanted parts on the print.
• Gloves, safety glasses, and other safety equipment: To keep you safe when painting.
• A wire, string, or a newspaper: If you use spray paint, hang the 3D print somewhere before spraying; a wire or a string can do the job well. To avoid mess, you can put your design on a newspaper using solid or liquid paint.

Before applying primers, you must know which material suits your 3D Print model. Here’s what you need to know about this step.

Step 2: Remove Unwanted Parts

You must first remove any supports to prepare the 3D-printed model for the painting. Eliminating lumps and ensuring a clean print is essential to ensure your 3D print is structurally and aesthetically correct. You can either use your bare hands or the following tools to remove unwanted parts:

• Craft knife 
• Sandpaper
• Tweezers
• Toothbrush
• Pliers

After removing unwanted parts, the next part is polishing or sanding the model’s surface. Continue reading the next section to learn more about the sanding process.

 Step 3: Sanding 3D Prints

Sanding your 3D-printed objects is the simplest method for creating attractive surface treatments. This method requires patience to achieve the finest results. 

Two options for polishing your 3D print are available: hand and electric sanding. Each option has advantages, so let's examine them both.

Hand Sanding 3D Prints

Hand sanding is a time-consuming but effective method to finish and enhance the appearance of your 3D prints. You can find sandpaper in supply stores, online, and even in your old toolbox, but you need sandpaper with varying grits for the best results. 

• The initial sanding should be performed with 150 to 220-grit paper. This can be done dry so that heat build-up that would cause the printed object to dissolve is avoided.
• Use sandpaper with 320-grit for the subsequent layer. Using a small quantity of water at this stage will assist in maintaining the object's coolness as you continue to work on it.

• Complete the sanding procedure with  600-grit sandpaper. Using water at this stage is advisable to prevent the print from melting.
• You can follow the 600-grit sandpaper with even finer sandpaper if you wish. Still, the surface will be incredibly smooth and devoid of layer lines.

Circular motions with the sandpaper or sanding block can prevent blemishes and an uneven finish. When sanding 3D-printed plastics, apply minimal pressure; the abrasive should do all the work.

Power Sanding 3D Printed Models

You can choose from various power tools to sand your 3D prints quickly and effectively. Some of these power tools include. 

• Belt sanders
• Orbital sanders
• Detail sanders

Much like hand sanding, you should start with medium-grit sandpaper and slowly work towards ultra-fine grits when using a power sander. You must take extra care to avoid heat build-up as you work, as power sanders move faster than your hands and generate more friction.

After learning how to sand, you may prime your 3D-printed model using the following instructions.

Step 4: Applying Primer Coat

Priming transforms your 3D print into a professional product and makes the painting process effortless by generating a flawless final surface. Using the following steps, find out how to properly apply a primer to your 3D prints.

1. Mount the part of the model: Drill a pilot hole in an inconspicuous location, place the component on a slender dowel, and then insert the dowel into the paint block.

2. Wash the model's surfaces to remove dust: Use a brush and water to wash away any dust. You may prefer to use deionized or distilled water to thoroughly clean the surface without leaving any spots.

3. Wipe down the model's surfaces with a tack cloth: While wearing nitrile gloves, gently run the tack cloth over the model's surface using long, gentle strokes. 

4. Mix the primer: Gently swirl the spray primer for 2 to 3 minutes in a circular motion. Avoid shaking, as this can mix the propellant into the solvent, resulting in bubbles in the coat when sprayed.

5. Spray the first coat of primer to the model: Spray in short, rapid strokes, 6-8” from the part. Start each stroke before the region and end the stroke after the part.

6. Inspect the first coat: With the primer on, inspect for areas needing additional sanding or filing. If sanding is necessary, repeat steps 5-6 to clean off dust before respraying.

7. Spray the final coat of primer: Add a second coat of paint using quick, light strokes until it becomes opaque. 

When making 3D prints, choosing a painting technique is essential. This opens up more possibilities for modification and refinement of the model. If you're still wondering what technique to use, you can choose from the options below.

Step 5: Choose a Painting Method

Realistic 3D printing relies heavily on the painting process. The result is an increase in originality. Hand-painting and Spray painting 3D Print are both prevalent techniques for decorating 3D prints.

There are three different techniques used in painting 3D Printed Models, including:

• Airbrushing- a technique of applying paint or dye on a surface on a 3D printed model. You can blend two or more colors, with one color gradually becoming another color.
• Spray painting: This technique is the quickest way to create even color shades across the surface.
• Hand painting: A technique best for 3D prints requiring fine details, such as toys or miniature models. Use good quality brushes and paint to coat your 3D image in your chosen colors.

Now that you've decided which technique to use, you can paint your 3D prints through these steps.

Step 6: Paint the 3D model

The success or failure of a work of art largely influenced the artist's painting technique.  It is possible to have a more modern look and increase the range of your resources by combining your paint and painting techniques. 

Read on to learn more about these techniques and the procedures involved in implementing them.

Spray Painting

The airbrush technique has become very popular among hobbyists and 3D printing enthusiasts because of its capability to apply finer coats of paint on 3D-printed models. This technique also allows producing various effects, like opaque, stains.

Painting 3D prints using an airbrush technique might sound challenging, but it is not impossible. It takes a little effort and some imagination to finish the object.

To efficiently apply paint on your 3d prints on your model, here are steps you can follow:

1. Start with the primed and mounted part.
2. Gently polish the surface until it looks glossy.
3. Clean off the dust using a tack cloth.
4. Get ready to paint: Put on your respirator and gloves. 
5. Stir your paint by gently swirling the internal mixing bead in the can for 2 to 3 minutes. 
6. Spray on the undercoat: Keep the nozzle approximately 6 inches away and move rapidly across the surface as you rotate the spray direction around the model. 
7. Let it sit for 20-30 minutes for the thin layer of paint to dry.
8. Polish between layers to delicately treat the model between paint coats. 
9. Mask off areas you want to preserve in the undercoat.
10. Apply the topcoat to create gradients and blend rich colors.
11. Finish with a clear coat to make the surface look glossy.

Hand Painting

Hand painting is usually the best choice for 3D prints that require fine details, such as toys or miniature models. You can use good-quality brushes and paint to coat your 3D print in your chosen colors. 

Be creative and ensure that the paint is diluted. Additionally, apply a layer and allow it to cure before proceeding. Here are some 3D Printing tips:

1. Start painting the more significant 3D printed parts.
2. Protect your eyes and hands (goggles and gloves) while painting.
3. Begin with bright areas and use bright paints at first.
4. Paint from the model's center and move to the outward parts.
5. Add shadows.
6. Add light accents at the end.
7. Clarify small details at last.

Overall, painting 3D prints with any form of paint should be enjoyable. After sanding and priming the project, you can accomplish a beautiful result through the next step.

Step 7: Add Finishing Touches

A light matte or gloss sealer coat is a great way to finish your project. It's the surest way to keep your artwork looking fresh for decades. Don't be afraid to try new things and use your imagination.

A spray of silver or gold can be used to make glittering effects. You may also apply an antique finish if you prefer a more old appearance. To further customize your painted 3D prints, add details like shadows and highlights or aged and rushed effects.

General Tips for 3D Printing

If you're seeking advice on how to paint 3D printing, consider the following:

• Print with the highest quality possible. The fewer flaws and layer lines a print has, the less time will be required to fill and sand the surface.
• If your paint is thick and challenging, apply a small amount of thinner. 
• Use wire to suspend or rotate the object on a stand without leaving fingerprints.
• If you manually rotate the object, apply primer and paint to that section last. Thus, you will not damage the paint's surface.
• Do not paint directly into 3D prints unless the paint's label specifies that it is compatible with plastic. 
• A dotting instrument can create circle shapes more precisely than a brush can. Additionally, it helps close open areas.
• If you run out of paint or need touch-ups in the future, you can color-match this swatch to recreate the same color.

Wrap-up

Painting 3D prints is a fantastic way to add a personal touch to your designs and exceptional creativity and artistry to your 3D printed models. It is easy but requires much time and planning to ensure the finest results.

Remember that much depends on how you smooth and lubricate your model beforehand. You have acquired the skills to paint 3D prints using acrylics and airbrushing. Now that you've mastered your skills, you can construct your 3D Print.