Smooth PLA 3D Prints: Tips and Tricks

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3D printing has revolutionized the way we create objects, from toys to medical implants and even entire buildings. However, 3D printed objects often have a rough surface finish with visible layer lines that can detract from the overall appearance of the final product. This is where PLA smoothing comes in.

PLA smoothing is the process of making the surface of PLA 3D prints smooth and even. There are several methods for achieving this, including sanding, polishing, and using various chemical treatments. The method you choose will depend on the desired level of smoothness, the size and complexity of the object, and the tools and materials you have available.

In this article, we will explore some of the most effective methods for smoothing PLA 3D prints. We will cover the tools and materials you will need, as well as step-by-step instructions for each method. Whether you are a beginner or an experienced 3D printing enthusiast, this guide will help you achieve a smooth and professional-looking finish on your PLA 3D prints.

Choosing the Right PLA Filament

When it comes to 3D printing, choosing the right filament is crucial to achieving the desired results. PLA (polylactic acid) is a popular material for 3D printing due to its ease of use, low cost, and eco-friendliness. However, not all PLA filaments are created equal. In this section, we’ll discuss how to choose the right PLA filament for your 3D printing needs.

Understanding Filament Diameter and Tolerance

The first thing to consider when choosing a PLA filament is its diameter. Most 3D printers use either 1.75mm or 2.85mm diameter filaments. It’s important to check your printer’s specifications to ensure you’re using the correct diameter filament. Using the wrong diameter filament can cause issues with extrusion and clog your printer’s nozzle.

Another important factor to consider is filament tolerance. Filament tolerance refers to the amount of variation in diameter that a filament can have. Most filaments have a tolerance of +/- 0.05mm, but some can have a tolerance of +/- 0.02mm or +/- 0.1mm. It’s important to choose a filament with a consistent diameter and tolerance to ensure reliable printing.

Selecting the Right Filament for Your Printer

Once you’ve determined the correct diameter and tolerance for your printer, you can start selecting the right PLA filament for your printing needs. PLA filaments come in a variety of colors and finishes, such as matte, glossy, or metallic. You can also find PLA filaments that are infused with additives like wood, metal, or glow-in-the-dark materials.

When selecting a PLA filament, consider the following factors:

  • Print quality: Look for a filament that produces high-quality prints with minimal warping or stringing.
  • Strength and durability: Consider the strength and durability of the filament for your specific application.
  • Temperature resistance: If you need to print objects that will be exposed to high temperatures, look for a PLA filament with a higher glass transition temperature (Tg).
  • Eco-friendliness: PLA is a biodegradable material, but some filaments may be more eco-friendly than others. Look for filaments made from renewable resources or recycled materials.

Overall, choosing the right PLA filament for your 3D printing needs requires careful consideration of factors like diameter, tolerance, color, finish, strength, durability, temperature resistance, and eco-friendliness. By selecting the right filament, you can ensure high-quality prints with minimal issues.

Optimizing Your Printer Settings

To achieve a smooth PLA 3D print, it is essential to optimize your printer settings. This section will provide you with some tips to help you calibrate your printer, adjust bed leveling, and fine-tune your print settings.

Calibrating Your Printer

Calibrating your printer is the first step to ensure that your 3D prints come out smooth. It is crucial to calibrate your printer’s X, Y, and Z-axis to ensure that the printer’s nozzle is at the correct height and distance from the print bed.

Here are some tips to help you calibrate your printer:

  • Use a calibration cube to check the printer’s accuracy
  • Adjust the printer’s belt tension
  • Check the printer’s pulleys and bearings
  • Ensure that the printer’s frame is rigid

Adjusting Bed Leveling

Bed leveling is essential to ensure that the first layer of your print adheres correctly to the print bed. If the bed is not leveled correctly, the print may warp or detach from the bed.

Here are some tips to help you adjust bed leveling:

  • Use a feeler gauge to measure the gap between the nozzle and the print bed
  • Adjust the bed leveling screws to ensure that the gap is consistent across the bed
  • Use a piece of paper to check the nozzle’s distance from the bed

Fine-Tuning Your Print Settings

Fine-tuning your print settings is essential to achieve a smooth PLA 3D print. You need to adjust the print speed, temperature, and layer height to ensure that the print comes out smooth and accurate.

Here are some tips to help you fine-tune your print settings:

  • Adjust the print speed to ensure that the print is not too fast or too slow
  • Adjust the temperature to ensure that the PLA filament melts correctly
  • Adjust the layer height to ensure that the print is not too thin or too thick

By following these tips, you can optimize your printer settings and achieve a smooth PLA 3D print.

Post-Processing Techniques

There are several post-processing techniques you can use to smooth out your PLA 3D prints. Here are some of the most popular methods:

Sanding Your Prints

Sanding is one of the most common ways to smooth out your PLA prints. You can use sandpaper or sanding sponges to remove any bumps or rough spots on the surface of your print. Start with a coarse grit sandpaper and gradually move to a finer grit until you achieve the desired smoothness.

When sanding, be sure to wear a dust mask or respirator to avoid inhaling any plastic particles. You can also wet sand your prints to reduce dust and debris.

Using a Heat Gun or Flame Torch

Using a heat gun or flame torch is another option for smoothing PLA prints. Simply point the heat source at the surface of your print and move it around in slow, even strokes. Be careful not to apply too much heat or hold the heat source too close to the print, as this can cause the plastic to warp or melt.

When using a heat source, it’s important to work in a well-ventilated area and wear heat-resistant gloves to protect your hands.

Using Chemicals to Smooth PLA

There are several chemicals you can use to smooth out your PLA prints, including acetone, isopropyl alcohol, and ethyl acetate. These chemicals work by dissolving the surface of the plastic, creating a smoother finish.

To use chemicals to smooth your prints, apply a small amount to the surface of your print and let it sit for a few minutes. Then, wipe away the excess with a clean cloth or paper towel. Be sure to work in a well-ventilated area and wear gloves to protect your skin.

It’s important to note that using chemicals to smooth PLA prints can be dangerous if not done properly. Always follow the manufacturer’s instructions and take proper safety precautions.


In conclusion, there are several effective ways to smooth PLA 3D prints. The best method for smoothing PLA depends on the desired finish, time constraints, and available resources.

Sanding and polishing are the most common methods for smoothing PLA 3D prints. It is a time-consuming process, but it yields excellent results when done thoroughly. With sanding, you are physically removing the layer lines, whereas with other methods, you are filling them in.

Another way to smooth PLA 3D prints is by using solvents like ethyl acetate. It is an effective method but requires careful handling and proper ventilation. Solvents like acetone do not work well with PLA and can cause it to disintegrate into small bits.

Heat treatment, specifically the annealing process, can also smooth PLA 3D prints. However, this method requires a controlled environment and specialized equipment.

Spray fillers, varnish, and epoxy resin are other methods for smoothing PLA 3D prints. They provide a glossy finish and fill in the gaps between the layer lines. However, they are not as effective as sanding and require more time and resources.

In summary, the best method for smoothing PLA 3D prints depends on the desired finish and available resources. Sanding and polishing are the most common and effective methods, while solvents, heat treatment, and spray fillers are other options. Whatever method you choose, make sure to follow safety precautions and handle the materials carefully.