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How to Smooth PLA 3D Prints

  • 5 min read

How to Smooth PLA 3D Prints? (Easy and Quick Guide)

PLA is popular in 3D printing for its ease of use and environmentally friendly properties, but its finished prints can often have visible layer lines and rough surfaces. This blog delves into four effective solutions on how to smooth 3D prints PLA, transforming them from rough, layered objects into sleek, refined creations. From heat-based techniques to tried-and-true tools, we’ll guide you through each method, ensuring that you have the know-how to elevate the finish of your PLA projects to the next level.

Why Should You Smooth PLA 3D Prints?

Smoothing PLA 3D prints is a crucial step for several reasons, all aimed at enhancing both the aesthetic and functional aspects of your 3D printed objects. Firstly, smoothing eliminates the layer lines and rough textures often present in 3D printed items, resulting in a more professional and polished appearance. This is particularly important for prints that are meant for display or as finished products.
Secondly, a smooth surface can improve the structural integrity and strength of the print. Layer lines can be weak points where breaks or cracks might occur; smoothing these out can reinforce the item and increase its durability.
In addition to these benefits, making PLA 3D prints smooth also opens up more possibilities for post-processing. A smoother surface is easier to paint, allowing for more intricate and detailed finishing work. This is especially useful for models and prototypes where precise color and finish are required.
Moreover, smoothing can also enhance the tactile feel of the print, making it more pleasant to handle – a significant factor for items like toys, household gadgets, or any object that will be frequently touched.
Overall, smoothing PLA 3D prints not only improves their visual appeal but also their physical properties, making it a valuable step in the 3D printing process.

How to Smooth PLA 3D Prints?

Having understood the importance of smoothing PLA 3D prints for enhanced aesthetics, durability, and post-processing potential, we now move on to the practical aspect: How to smooth out PLA 3D prints? Here are the 4 best ways to smooth PLA 3D prints for your reference.


Sanding PLA 3D prints involves using sandpaper of varying grits to eliminate layer lines and achieve a smoother finish.
  • Begin with coarse grit (around 100-200) to remove prominent lines, gradually moving to finer grits (400-800) for a smoother surface. Use circular or linear motions while sanding, focusing on areas with visible lines or imperfections.
  • Follow up with even finer grits for a polished finish. Wet sanding, done with water or soapy water, reduces dust and helps achieve a smoother surface.
  • However, sanding can be labor-intensive, time-consuming, and might compromise fine details. Consider combining sanding with other methods like heat-based techniques or using fillers for a more efficient and refined finish when smoothing out PLA 3D prints.
Remember, proper ventilation and using safety equipment like masks and goggles are crucial when sanding PLA to avoid inhaling particles or getting debris in your eyes.

Surface Melting

Smooth 3D prints PLA via surface melting is achieved by using heat to melt and blend the surface layers, reducing visible lines. Here's how you can smooth PLA 3D prints by surface melting:
  • Prepare your work area to ensure your work area is well-ventilated, as melting PLA can produce fumes. Also, have heat-resistant gloves and safety glasses for protection.
  • Turn on your heat gun or hair dryer and hold it at a safe distance from the print – usually a few inches away. Move the heat source steadily over the surface of the print. The goal is to apply enough heat to slightly melt the outer layer of the PLA, causing it to smooth out, but not so much that it warps or deforms the print.
  • Keep a close eye on the print as you apply heat. PLA will start to become glossy as it reaches the melting point. Once you notice this change, move the heat source to another area to avoid overheating any one spot.
  • After you have evenly treated the entire surface, turn off the heat source and let the print cool down. As it cools, the PLA will solidify again, retaining the new, smoother surface.

Surface Coating

Surface coating, like using epoxy resin or specialized coatings, can smooth PLA 3D prints by filling gaps and irregularities, providing a uniform finish.
  • Clean the print thoroughly to remove dust and debris. Select a suitable coating material, such as epoxy resin, spray filler, or a specialized 3D print smoothing product.
  • Use a brush or spray to apply the coating evenly across the surface of the print. If using a brush, apply in thin, even layers. For spray coatings, maintain a consistent distance and motion to avoid drips.
  • After the first layer of coating is applied, let it dry completely. Check the surface; if layer lines are still visible, apply additional coats until the desired smoothness is achieved.
  • Once the final coat is dry, lightly sand the surface for an even smoother finish. You can then proceed to prime and paint the print for a professional appearance.

Chemical Smoothing

How to make PLA 3D prints smooth thoroughly? Chemical smoothing is the desired method that uses specific chemicals to dissolve the outer layers of the PLA, creating a smooth and glossy surface. Here are four steps to achieve this:
  • Select the right chemical. For PLA, chemicals like ethyl acetate or THF (Tetrahydrofuran) are commonly used.
  • Before applying the chemical, clean the print to remove any dust or grease. Ensure you have safety equipment like gloves and goggles on hand, and work in a well-ventilated space or under a fume hood to avoid inhaling fumes.
  • Apply the chemical using a brush or by submerging the print in a chemical bath. If brushing, apply a thin and even coat over the print. For a chemical bath, submerge the print for a short, controlled duration. The time required will vary based on the chemical's strength and the desired level of smoothness.
  • After the chemical treatment, thoroughly rinse the print with water to remove any residual chemicals. Then, let it dry completely. The PLA will solidify again, leaving a smoother and shinier surface.
Summarizing the methods to smooth PLA 3D prints, it's clear that achieving a refined finish is a key aspect of 3D printing. For enthusiasts seeking to produce smoother prints right from the start, the AnkerMake M5C 3D Printer stands out. Its capability to print at up to 300℃ with AnkerMake PLA+ Filament allows for a superior printing experience. The printer's all-metal hotend ensures consistent high-temperature performance, ideal for detailed and smooth prints. With options for different modes, including Precision and Fast, and varying nozzle sizes and layer thicknesses, the AnkerMake M5C offers unparalleled control over print quality and resolution, making it an excellent choice for those aiming to produce smooth, high-quality PLA 3D prints.


Perfectly smoothing PLA 3D prints opens a realm of possibilities for creators. Whether employing sanding, heat-based methods, chemical treatments, or surface coatings, each technique refines the prints, elevating their quality and visual appeal. Embracing these methods empowers enthusiasts to transform raw prints into professional-grade models, enhancing their aesthetics and functionality across diverse applications.


What temperature will PLA soften?

PLA (Polylactic Acid) softens around 60 to 65 degrees Celsius (140 to 149 degrees Fahrenheit), making it susceptible to deformation or becoming malleable at these temperatures.

How can PLA prints be smoothed without the use of sandpaper, solvents, or paint?

PLA prints can be smoothed using a heat gun or a handheld torch. Pass the heat source over the surface in a consistent motion, melting and smoothing the PLA. Caution and control are essential to prevent overheating or warping.

Can you smooth PLA with hot water?

Hot water can soften PLA slightly but isn't effective for smoothing prints significantly. Submerging PLA prints briefly in hot water (below its glass transition temperature) may make them slightly more malleable, but it won't provide a substantial smoothing effect like other methods.