PLA vs ABS vs PETG: A Comparison of 3D Printing Filaments

One of the most important decisions to make when it comes to 3D printing is material choice. Each filament has its own set of properties and printing parameters,  as well as benefits and limitations. In this guide, we’re looking at the three most commonly used filaments in 3D printing: PLA, ABS, and PETG to better understand their properties, advantages (and disadvantages), best practices for filament choice, and more. 

PLA, ABS, and PETG each have distinct characteristics that make them suitable for different applications. PLA is known for its biodegradability and ease of use, making it a popular choice for both beginners and professionals. ABS, for its part, is prized for its durability and good flexural strength, making it ideal for more demanding projects. Last but not least, PETG offers a combination of strength, flexibility, and chemical resistance, which make it a good choice for a versatile range of applications. 

1. Understanding 3D Printing Filaments

1.1 What are 3D Printing Filaments?

When we talk about 3D printing filament, we’re referring to a class of thermoplastic materials used as the raw material for fused deposition modeling (FDM) 3D printers. In the FDM printing process, filament is fed into a print head, where it is subsequently melted and extruded through a nozzle. The extruded material is deposited onto a build surface, solidifying as it cools. The deposition process is repeated layer by layer to create a three-dimensional object. 

Today, there are many types of thermoplastic filament available to makers and professional users, each with its own unique set of properties. As we’ll see in further detail, these properties, such as melting temperature, strength, and flexibility, play a significant role in determining the applications the material is viable for. Furthermore, choosing the right print settings for each material can play a significant role in the final 3D print’s quality and strength.

1.2 Types of 3D Printing Filaments

PLA, ABS, and PETG are three of the most commonly used filaments used in FDM 3D printing.

PLA (Polylactic Acid) is a biodegradable thermoplastic derived from renewable sources, like cornstarch and sugarcane. With a low melting temperature of around 200-220°C, PLA is an easy material to print on virtually all desktop FDM 3D printers, making it the go-to choice for beginners and those looking for a more eco-friendly option. In terms of usage, PLA is commonly used for prototyping, decorative models, and low-stress applications. The tensile strength of PLA is around 7,250 psi, and its elongation at break is approximately 6%. PLA is also known for its ability to produce detailed prints with a smooth finish, and it has a low shrinkage rate, reducing the chances of warping during printing.

ABS (Acrylonitrile Butadiene Styrene) is a petroleum-based thermoplastic that offers high strength, ductility, and temperature resistance. ABS has a higher melting point than PLA and thus requires a higher printing temperature (around 220-250°C) and can benefit from a heated print bed in order to minimize warping and ensure proper bed adhesion. 3D printed ABS has applications in functional prototyping, tooling, and end-use components. The tensile strength of ABS is around 4,600 psi,[1] while its elongation at break is about 20%, making it more impact-resistant than PLA. 

PETG (Polyethylene Terephthalate Glycol) is a copolymer that combines PET (Polyethylene Terephthalate) and glycol. PETG is known for its good adhesion, durability, and chemical resistance. PETG requires a relatively high printing temperature, of around 220-260°C, and prints well on both heated and non-heated print beds. PETG is commonly used for functional prototypes (for instance in the packaging industry), as well as electrical enclosures, tooling components, and more. PETG has a tensile strength of around 7,250 psi and a high elongation at break (>20%), making it stronger and less brittle than both PLA and ABS. Additionally, PETG has a glass transition temperature of around 80°C, which allows it to maintain its properties at moderately high temperatures.

Recommended reading: The Ultimate Guide to Types of 3D Printing Materials

Having a good grasp of different filament properties will ensure you use the right material for a given application.

2. PLA (Polylactic Acid)

2.1 Overview and Properties

PLA is a biodegradable thermoplastic derived from renewable resources like cornstarch and sugarcane. It has gained popularity in the 3D printing community due to its ease of use, environmentally friendly nature, and versatility. PLA is particularly well-suited for beginners in 3D printing, as it does not require the use of high print temperatures (or a heated print bed) and has minimal warping issues compared to other filament materials.

One of the material’s key properties is its low melting temperature, which typically ranges between 200 and 220°C. This lower temperature requirement makes it easier to print with, as it reduces the chances of clogging and does not require high-end 3D printers (with enclosures and heated beds) to achieve good print results. Furthermore, PLA exhibits a low shrinkage rate, which means it is less likely to warp during the printing process. This is particularly advantageous when printing large objects or objects with a large surface area in contact with the print bed.

In terms of mechanical properties, PLA has a tensile strength of around 7,250 psi, making it a reasonably strong material for lightweight applications. However, its elongation at break is only about 6%, meaning that it is more brittle than other filaments like ABS and PETG. This brittleness may limit its use, particularly for applications that require impact resistance or load bearing capabilities.

As a plant-based thermoplastic, PLA is also known for its biodegradability, which sets it apart from petroleum-based filaments like ABS. Under the right conditions, PLA can break down into its constituent components within a few months to a few years. This environmentally friendly aspect makes PLA an appealing choice for users who are conscious of the environmental impact of their 3D printing activities.

2.2 Advantages of PLA

There are several advantages associated with using PLA 3D printing filament that explain why the material is so popular amongst makers. Let’s take a look.

• Ease of Printing: PLA's low melting temperature of around 200-220°C makes it an easy material to print with. The filament can easily be used on most desktop FDM 3D printers, and has good results without the need for any special modifications or hardware, such as a heated bed or print enclosures. The fact that PLA does not require a heated bed not only simplifies the printing process, it also reduces energy consumption.

• Low Warping and Shrinkage: PLA is known for its low shrinkage rate during the cooling process, which reduces the risk of warping. This property is particularly beneficial for printing large objects or objects with a significant surface area. The low warping tendency of PLA also contributes to better layer adhesion and improved print quality.

• Biodegradability: PLA is made from renewable plant-based resources like cornstarch and sugarcane. The material is also considered biodegradable under the right conditions (read more on that here). This environmentally friendly aspect makes PLA an attractive option for users who are conscious of their 3D printing plastic consumption.

• Aesthetic Appeal: PLA is available in a wide range of colors and finishes, including translucent and metallic options. It produces prints with a smooth surface finish and good detail resolution. This makes PLA an ideal choice for decorative items, toy models, visual prototypes, and any application where aesthetics are important.

• Odorless Printing: Unlike some other 3D printing materials, PLA does not produce any unpleasant odors during the printing process. On top of that, its VOC and UFP emissions in the printing process are very low. This makes it a safe 3D printing material to work with, especially in environments with limited ventilation.

• Food Safe: Some PLA filaments are considered food-safe, which means they can be used to create items that come into contact with food. This property expands the range of potential applications for PLA, including the creation of custom cookie cutters, cake toppers, and other kitchenware. However, it is essential to verify the food-safe status of a particular PLA filament before using it for such purposes as well as consider other risk factors in the 3D printing process.

Recommended reading: Food-grade 3D Printing: Is PLA Food-Safe?

2.3 Disadvantages of PLA

Despite its many advantages, PLA also has some drawbacks that users should consider before picking it as their filament of choice for certain applications.

• Limited Durability: As we’ve seen, PLA is a brittle material that consequently has little impact resistance. That property, paired with low heat temperature resistance and chemical resistance, make for a material that has limited durability and can break or degrade easily.

• Temperature Sensitivity: PLA has a low glass transition temperature, typically around 60-65°C. This means that printed parts made from PLA can soften or deform when exposed to temperatures in that range. This limits PLA to applications that do not involve exposure to heat, such as outdoor use or parts for electronic devices that generate heat.

• Lower Chemical Resistance: Compared to other filaments, PLA has lower resistance to certain chemicals, such as acetone and other solvents. In many cases, PLA can actually start to dissolve when exposed to certain chemicals, like ethyl acetate. This can limit its viability for applications where the printed part may come into contact with chemicals or need to withstand exposure to solvents.

• Moisture Absorption: PLA is hygroscopic, which means it can absorb moisture from the air. Humidity can therefore compromise PLA filament’s material properties and quality, and can lead to inconsistent print results and reduced mechanical properties. Considering this, it is important to store PLA filament spools in a dry environment to prevent moisture absorption or use a filament dryer before printing.

• Degradable: While PLA's biodegradability is often considered an advantage, it can also be a drawback in some applications. For example, if a PLA printed part is used outdoors or in environments with high humidity, the degradation process may occur more quickly than desired, leading to a shorter lifespan for the part.

• Post-Processing Limitations: PLA's lower melting temperature and brittleness make it less suitable for certain post-processing techniques, such as acetone vapor smoothing or heat-based treatments. This may limit the range of finishes and appearances achievable with PLA prints compared to other filament materials.

3. ABS (Acrylonitrile Butadiene Styrene)

ABS is another popular filament choice in the world of 3D printing. It is known for its durability, strength, and heat resistance, making it suitable for a wide range of applications. In this section, we will discuss the overview and properties of ABS, as well as its advantages and disadvantages.

3.1 Overview and Properties

ABS is a petroleum-based thermoplastic polymer consisting of three primary organic compounds: acrylonitrile, butadiene, and styrene. The combination of these compounds results in a material that offers a balance of strength, as well as impact, heat, and chemical resistance.

ABS has a tensile strength of approximately 4,700 psi, which you may have noticed is less than PLA. Despite its lower tensile strength, ABS is still considered a stronger material due to its superior flexural strength and durability. Additionally, ABS has a high impact resistance, which is particularly useful for applications that require the printed part to be able to absorb shock or impact.

ABS has a high glass transition temperature of about 105°C , especially when compared to PLA. This means that it can maintain its shape and structural integrity even when exposed to high temperatures. As a result, ABS is a better choice for applications that require heat resistance or for parts that will be exposed to high temperatures. ABS also exhibits good resistance to a wide range of chemicals, including many solvents, oils, and acids, making it suitable for applications in corrosive or harsh environments.

When it comes to post-processing, ABS can be easily finished using various techniques, such as sanding, filing, and vapor smoothing with acetone. This allows for a greater range of finishes and appearances in the final product.

It is worth noting that ABS is less environmentally friendly than PLA, as it is derived from petroleum and is not biodegradable. It also has a higher printing temperature requirement, which can lead to potential issues such as warping during the printing process. We will discuss the advantages and disadvantages of ABS in the upcoming sections.

3.2 Advantages of ABS

There are several key advantages to using ABS filament in 3D printing, which contribute to its popularity among hobbyists and professionals alike.

• Toughness and Durability: One of the primary advantages of ABS is its toughness and durability. Although ABS has a lower tensile strength than PLA, the material is far less brittle, resulting in good impact resistance and durability. These properties translate well to applications that require robust and long-lasting parts. The material’s higher melting temperature also contributes to its durability.

• Heat Resistance: ABS has a glass transition temperature, around 105°C, which allows it to maintain its shape and structural integrity even under higher temperatures. This characteristic is particularly useful for parts that need to withstand heat exposure or for applications that require thermal stability. We should point out that ABS is not naturally UV resistant, however many filaments have UV resistant additives, which make the material suitable for outdoor applications and sun exposure.

• Chemical Resistance: ABS exhibits good resistance to a variety of chemicals, including oils, and certain acids. That said, ABS is considered to be soluble when exposed to some chemicals, like acetone. Acetone is therefore a common ingredient used to smooth and finish ABS components, since it can eliminate surface inconsistencies, like layer lines.

• Post-Processing Capabilities: The ease of post-processing with ABS is another advantage, as it can be sanded, filed, and smoothed using various techniques like vapor smoothing with acetone. This allows for greater customization and flexibility in achieving different finishes and an all around superior quality in the final product.

• Electrical Insulation: ABS also has good electrical insulation properties, which can be beneficial for applications requiring electrical components or parts that must be electrically isolated, such as enclosures or housings.

• Compatibility: ABS is compatible with many FDM 3D printers on the market, making it a versatile and accessible filament choice for a range of users. The filament does work best on systems with a heated print bed.

3.3 Disadvantages of ABS

Now that we’ve seen ABS’ numerous advantages, we also want to consider its drawbacks, so that you have all the information you need when selecting a filament for your next 3D printing project. Some of the disadvantages of ABS include:

• Fumes: ABS emits potentially harmful fumes when it is melted during the printing process, with the primary odor-causing components being styrene and butadiene. These fumes can contain volatile organic compounds (VOCs), which are not only unpleasant to smell, they may also pose health risks if proper ventilation is not provided. It is thus essential to print in a well-ventilated area or use a printer equipped with a filtration system to minimize exposure to these emissions when using ABS.

• Warping: ABS has a higher shrinkage rate compared to PLA, which can lead to warping and dimensional inaccuracies in printed parts. This shrinkage occurs as the material cools and contracts after being extruded. To mitigate warping, it is often necessary to use a heated build platform, typically set at a temperature between 95°C and 110°C, and enclose the printer to maintain a consistent temperature during the printing process.

• Adhesion: Achieving optimal adhesion with ABS can be challenging. Unlike PLA, which usually adheres well to a variety of print bed surfaces, ABS may require additional steps to ensure proper adhesion. This may include applying an adhesive layer to the print bed, such as a dedicated print bed adhesive or tape, or using specialized bed surfaces, like BuildTak or PEI sheets.

Recommended reading: 3D Print Not Sticking to Bed? Here’s the Solution

• Higher Printing Temperature: ABS requires a higher printing temperature, typically between 220°C and 250°C. This higher temperature may not be compatible with all 3D printers or print heads, particularly those designed for lower-temperature materials like PLA.

• Non-renewable: ABS is made from non-renewable resources like petroleum, which makes it less environmentally friendly than bio-based alternatives like PLA. Additionally, ABS is not biodegradable and may contribute to plastic waste if not properly recycled. (We should note that most community recycling programs do not process ABS, as specialized facilities are required.)

In the end, it is crucial to weigh the advantages and disadvantages of ABS when deciding on the most appropriate filament for a given project. Each application may have specific requirements that make one filament type more suitable than another, and understanding the unique properties of ABS is an essential step in making an informed decision.

ABS offers properties, like good temperature resistance, durability, and impact strength.

4. PETG (Polyethylene Terephthalate Glycol)

4.1 Overview and Properties

PETG is a popular 3D printing material that combines some of the benefits of both PLA and ABS and addresses some of their drawbacks. It is a modified version of polyethylene terephthalate (PET), a common plastic used in many consumer products, including water bottles and food packaging. The addition of glycol to the polymer chain results in a material that is more pliable, less brittle, and easier to print than standard PET.

PETG has several notable properties that make it a desirable choice for 3D printing. It is a highly durable material, offering excellent impact resistance and mechanical strength. PETG has a tensile strength of around 7,250 psi, which is comparable to that of PLA. Its elongation at break is typically between 20% and 30%, indicating its ability to withstand significant deformation before breaking, making it more durable and tough than brittle PLA.

One of the key advantages of PETG is its excellent layer adhesion. This property allows printed parts to maintain their structural integrity even when subjected to stress or impact. Additionally, the material's low shrinkage rate minimizes warping and improves print accuracy.

The optimal printing temperature for PETG ranges between 220°C and 260°C, with a heated bed temperature of around 65°C to 90°C. This temperature range is compatible with most 3D printers, making it a versatile option for a wide array of applications. It is also worth noting that the raw material PETG is considered food-safe. When printed under the right conditions, it can be suitable for projects involving food contact or storage.

4.2 Advantages of PETG

PETG offers several advantages that make it an attractive option for 3D printing enthusiasts and professionals alike. 

• Ease of Printing: One of the most significant benefits is its excellent balance between ease of printing and mechanical properties. PETG combines the user-friendly nature of PLA with the strength and durability of ABS, providing a versatile material that can cater to a wide range of applications.

• Good Layer Adhesion: The outstanding layer adhesion of PETG is another advantage that sets it apart from other 3D printing materials. This property results in printed parts that are less prone to delamination or splitting, even when subjected to stress or impact. The strong interlayer bonding also contributes to the material's overall durability and toughness, making it suitable for functional prototypes and end-use parts.

• Impact Resistance: PETG boasts a high tensile strength (around 7,250 psi) as well as good elongation at break (>20%), which results in excellent impact resistance and mechanical strength. PETG is known for its toughness and durability, and can withstand significant forces and deformation before breaking. 

• Food-Safe: PETG is a non-toxic material and is considered food-safe when printed under the right conditions. This attribute makes it suitable for applications involving food contact or storage, such as kitchen utensils, containers, or even custom-shaped molds for culinary purposes.

4.3 Disadvantages of PETG

Despite the numerous advantages PETG offers, there are some disadvantages that users should be aware of when considering this material for their 3D printing projects. 

• Stringing: One of the main drawbacks is that PETG tends to be more prone to stringing compared to other materials. This issue arises due to the material's viscosity and can lead to imperfect surface finishes on the printed parts. To mitigate this problem, users must fine-tune their retraction settings and print temperatures to find the optimal balance. 

• Slower to Print: The best results when printing PETG come when printing at a slower rate. Slow print speed contributes to the material's excellent layer adhesion and overall strength, though it may not be ideal for users who prioritize rapid prototyping or production. It is crucial to consider the trade-off between print speed and material properties when deciding whether PETG is the right choice for a particular project.

• Food Safety: Although PETG is considered a food-safe material under the right conditions, it is essential to note that not all PETG filaments are equal in this regard. The manufacturing process, additives, and colorants used in the production of the filament can impact its food-safe status. Users must ensure that they source their PETG filament from reputable suppliers and verify its food-safe certification before using it for applications involving food contact.

• Post-Processing Limitations: PETG is not as easy to post-process as some other materials, particularly because it does not respond to common solvent-based smoothing methods, like acetone smoothing. Users may need to explore alternative post-processing techniques or accept a slightly rougher surface finish when working with PETG.

5. Comparing PLA, ABS, and PETG

Now that we’ve had a detailed look at the three material contenders, let’s compare them side by side. Ultimately, understanding the differences in their strengths and weaknesses will enable users to make informed decisions and choose the most suitable material for their specific applications.

5.1 Strength and Durability

Strength and durability are critical factors to consider when comparing PLA, ABS, and PETG filaments. 

PLA, a biodegradable and eco-friendly material, exhibits a relatively high tensile strength, but its overall durability and impact resistance are lower compared to ABS and PETG. Due to its brittleness, PLA is not an ideal choice for parts that require high impact resistance or long-term durability under varying environmental conditions.

ABS, for its part, is known for its high impact resistance and durability. It has a lower tensile strength than PLA but has a substantially greater elongation at break, meaning it can be stretched or bent more before breaking. This characteristic makes ABS a suitable choice for parts that need to be both strong and resilient.

In a sense, PETG combines the best of both PLA and ABS, offering high tensile strength, durability, and impact resistance. Furthermore, PETG demonstrates superior layer adhesion compared to both PLA and ABS, which contributes to its overall strength and durability. This combination of properties makes PETG a versatile choice for various applications, including those that require a balance of strength, impact resistance, and long-term durability.

In the end, if strength and durability are top priorities for your 3D prints, PLA might not be the best option. Its brittleness means that parts can break when exposed to stresses. ABS, meanwhile, has excellent impact resistance and durability. PETG perhaps offers the best of both worlds, with good tensile strength as well as impact resistance and durability. We should mention that these superior properties are also reflected in the cost of PETG, which is typically greater than ABS.

5.2 Print Quality and Ease of Use

When choosing a filament material for 3D printing, print quality and ease of use are also important factors to consider. These characteristics can significantly impact the success of a project and the overall experience of working with the material.

PLA is well-known for its ease of use and ability to produce high-quality prints with minimal warping and stringing. It has a lower printing temperature and is compatible with virtually all desktop 3D printers. The lower melting point also reduces the likelihood of clogging and simplifies bed adhesion. Additionally, PLA prints exhibit sharp edges and fine details, making it a popular choice for projects that require high-resolution and intricate designs.

ABS can be more challenging to work with due to its higher printing temperature. The material not only requires higher temperatures to print, which can create challenges for some hobbyist-grade systems, it is also prone to bed adhesion problems and warping, particularly if the printing environment is not adequately controlled. Enclosed 3D printers and heated beds are often recommended to mitigate these problems. ABS also produces a strong odor during the printing process, which can be a concern in poorly ventilated spaces. However, when properly managed, ABS can yield high-quality prints with excellent durability and impact resistance.

PETG offers a good balance between print quality and ease of use, as it combines toughness and durability with good bed adhesion and low warpage. PETG typically prints at temperatures between 220°C and 260°C and demonstrates strong layer adhesion and minimal warping. That said, PETG can be more prone to stringing and oozing than PLA, requiring careful fine-tuning of printer settings for optimal results. It can also sometimes adhere too well to certain print surfaces, making part removal tricky. With the right settings and print surfaces, however, PETG can produce high-quality prints with excellent strength and durability and without much hassle.

In summary, PLA excels in ease of use and print quality, making it an ideal choice for beginners and projects that require intricate details. In fact, it is widely recognized as the easiest material to 3D print. While ABS has its benefits, it generally can be more challenging to print due to its higher temperature requirements and potential for warping. Finally, PETG provides a balance between print quality and ease of use, with strong, durable prints suitable for various applications. 

5.3 Environmental Impact

When evaluating 3D printing materials, it is crucial to consider the environmental impact of each filament. Factors such as biodegradability, energy consumption during production, and recycling play a significant role in determining the sustainability of these materials. 

PLA has a distinct advantage in terms of its environmental impact, because it is derived from renewable plant-based resources like cornstarch and sugarcane. This makes it a more sustainable option compared to non-renewable petroleum-based filaments. PLA can also biodegrade under industrial composting conditions, typically breaking down within six months to two years. It should be noted that PLA's biodegradability is significantly reduced in landfills due to the lack of optimal composting conditions, so simply throwing away a 3D print still has an ecological impact. Nonetheless, PLA's renewable source and biodegradability make it a more environmentally friendly option among common 3D printing materials.

ABS, being a petroleum-based plastic, has a higher environmental impact compared to PLA. The production of ABS relies on a nonrenewable resource whose extraction consumes substantial energy and generates emissions. Furthermore, ABS is not biodegradable, and its disposal in landfills can contribute to environmental pollution. Although ABS can be recycled, the recycling process is energy-intensive and not as widely accessible as recycling for other plastics like PET. These factors make ABS a less environmentally friendly option compared to PLA and PETG.

PETG, like ABS, is also derived from petroleum-based resources. And while it is technically recyclable, it is not often accepted by municipal recycling centers (this is despite it’s similarity to fully recyclable PET). That said, it is possible to seek out PETG filaments made from recycled materials.

In conclusion, PLA stands out as the most environmentally friendly option among the three 3D printing materials, primarily due to its renewable origin and biodegradability. PETG offers a more sustainable alternative to ABS due to the fact that is is easier to recycle. ABS, on the other hand, has a higher environmental footprint, mainly due to its petroleum-based production, non-biodegradability, and limited recycling potential.

While most thermoplastics are technically recyclable, many cannot be processed at your standard recycling facility.

6. Choosing the Right Filament for Your Project

Selecting the best filament for a 3D printing project is crucial to achieving the desired outcome. Here are some of the factors you should think about when choosing a filament, including mechanical properties, printing conditions, and environmental impact.

6.1 Filament Selection Tips

When selecting a filament for your 3D printing project, it’s not always viable to use what’s lying around. Different applications have different requirements, so it’s a good idea to pick a filament that lines up with your print’s needs.

First, think about the functional requirements of the object you are printing. Will it need to withstand high levels of stress, impacts, or temperature fluctuations? If so, you may want to consider a more robust material like ABS or PETG. If the object is primarily decorative or a prototype for testing form and fit, PLA may be a suitable choice due to its ease of printing and wide range of colors and finishes.

Next, take into account the printing environment and equipment you have available. Some materials, like ABS, require a heated bed and an enclosed printing environment to minimize warping and ensure successful prints. If your 3D printer does not have these features or if you are inexperienced with more challenging materials, PLA or PETG might be more appropriate choices.

The dimensional accuracy of the printed object is another factor to consider. If your project requires tight tolerances and precise dimensions, it is essential to choose a filament with minimal shrinkage during the cooling process. PLA is known for its low shrinkage rate, while ABS may require more post-processing and calibration to achieve the desired dimensional accuracy. If you need strength and good dimensional accuracy, PETG could be the way to go.

You should also consider the post-processing options available for each filament. If you need a smooth, glossy finish or plan to paint your object, assess how easy it is to sand, paint, or chemically smooth each material. As mentioned earlier, PLA can be sanded and painted but not chemically smoothed, while ABS can be sanded, painted, and smoothed using acetone vapor. PETG can be sanded and painted, but its chemical smoothing options are limited.

By evaluating these factors and understanding the unique properties of each filament, you can make an informed decision and select the most suitable material for your 3D printing project. This will help ensure successful prints and high-quality results that meet your specific requirements.

7. Best Practices for Printing with PLA, ABS, and PETG

7.1 Printer Settings and Calibration

No matter what material you are 3D printing, it is vital to apply the right 3D printer settings and properly calibrate your printer to ensure high-quality prints. Properly calibrating your printer and adjusting settings to match the material being used can significantly impact the success of your project. Here are some important factors to consider when working with PLA, ABS, or PETG.

Temperature Control

There are a couple of print temperatures to be aware of before initiating your 3D print. First, the extrusion temperature (aka print temperature) refers to the temperature of the print nozzle. Every 3D printer filament has a temperature range that works best, and it can vary depending on the brand of filament. Choosing the right print temperature will ensure a steady flow of melted filament, without any risk of over extrusion or burning. 

As we’ve covered, PLA has the lowest print temperature of the three filaments, and works best between 200 and 220°C. To give you an idea of how different brands can vary, Ultimaker suggest a print temperature between 200 and 210°C for Ultimaker PLA [2], while Fillamentum PLA Extrafill prints best between 190– 210°C.[3]

ABS has a higher print temperature range, typically between 220–250°C. Again, this can vary based on the specific type of ABS filament. For example, Ultimaker recommends between 225 and 260°C for its ABS filament [4], while Polymaker has a higher bracket between 245 and 265˚C for its PolyLite ABS.[5]

Similar to ABS, PETG also has a higher print temperature, with its optimal range falling between 220 and 260°C. However, PETG has a slower cooling process which reduces the risk of warping. If we look at Prusament PETG, a nozzle temperature of 250 °C is recommended [6], while Ultimaker PETG is slightly cooler at 225-245°C.[7]

In addition to the extruder temperature, it's important to consider the temperature of the print bed. PLA usually prints well on a heated bed at 40-60°C, while ABS requires a higher bed temperature, typically between 95-110°C, to help prevent warping. PETG benefits from a heated bed temperature of 65-90°C (start on the lower end), which helps maintain the material's dimensional stability and adhesion to the print surface.

Print Speed

Print speed refers to how fast the print head moves along the X and Y axes and deposits material on the build surface. It goes without saying that adjusting the print speed can have a significant impact on the quality of your prints. For example, printing too quickly can result in poor layer adhesion, under extrusion, ringing, and poor dimensional accuracy. Printing too slowly is typically associated with fewer problems, but it can lead to issues like part deformation. 

PLA can generally be printed at faster speeds, ranging from 60-150 mm/s (though this upper limit is more experimental). ABS benefits from slightly slower speeds, around 40-60 mm/s, to ensure strong layer bonding and to avoid delamination. PETG typically prints best at moderate speeds, around 40-60 mm/s, to balance print quality and speed.

Recommended reading: 3D print speed: What it is and why it matters

Layer Height and Cooling

Layer height and cooling settings also play a vital role in determining the final appearance and strength of your 3D prints. PLA, due to its low shrinkage, can be printed with a wide range of layer heights, from 0.1 to 0.3 mm, depending on the desired resolution and print time. A cooling fan is usually used to solidify the layers quickly and prevent deformation.

ABS, on the other hand, can benefit from a smaller layer height and slower cooling to minimize warping and promote adhesion between layers. Layer heights between 0.1 and 0.2 mm are common for ABS, and cooling fans should be used with caution or turned off entirely to maintain a stable print temperature. 

PETG can be printed with layer heights similar to PLA and ABS, typically between 0.1 and 0.3 mm. However, it is crucial to adjust cooling settings carefully to prevent excessive warping or stringing. A moderate cooling fan setting is generally recommended for PETG to balance layer cooling and adhesion.

By carefully calibrating your 3D printer and adjusting the settings to match the specific filament being used, you can set yourself up for a successful 3D print.

7.2 Post-Processing Techniques

Post-processing techniques can be used strategically to enhance the appearance, functionality, and durability of 3D printed objects made from PLA, ABS, and PETG. Various techniques can help remove surface imperfections, achieve a smooth finish, and improve the overall aesthetic of the final product. Here, we delve into some of the post-processing techniques applicable to PLA, ABS, and PETG prints.

Sanding

Sanding is a common technique used to smooth out the surface of 3D printed objects. This method is effective for PLA, ABS, and PETG prints, though with varying degrees of ease. (Many makers cite ABS and PETG as easier to sand than PLA, which is less temperature resistant.) To sand 3D prints, start with a coarse grit sandpaper (around 100-200 grit) and working up to a fine grit (around 800-1000 grit) to achieve a smooth finish. Sand in a circular motion, applying even pressure as you go to ensure an even surface. 

Acetone Smoothing

For ABS prints, smoothing post-processes, like acetone vapor, are popular to achieve a smooth, glossy finish. Acetone vapor dissolves the outer layer of the ABS print, smoothing out the surface and fusing the layers together. This method can improve the object's appearance and structural integrity. However, proper safety precautions, such as adequate ventilation and protective equipment, must be taken when working with acetone. Note that PLA and PETG prints are not compatible with acetone vapor smoothing, as these materials do not dissolve in acetone. 

Priming and Painting

Applying a primer and paint can enhance the appearance of PLA, ABS, and PETG prints while also providing additional protection against wear and environmental factors. Before applying primer, ensure the object's surface is clean and free of debris. A thin layer of primer can be applied using a spray can or brush. After the primer has dried, a light sanding with fine-grit sandpaper can help achieve a smooth surface. Finally, apply the desired paint color, following the manufacturer's instructions for best results.

Annealing

Annealing is a heat treatment process that can improve the mechanical properties of PLA, ABS, and PETG prints, such as strength and heat resistance. By slowly heating the printed object in an oven at a specific temperature (typically around 60-70°C for PLA, 105-107°C for ABS, and 80-100°C for PETG) and then allowing it to cool down gradually, the material's crystalline structure is altered, resulting in improved performance. However, care must be taken to avoid warping or deformation during the annealing process. 

By using these post-processing techniques, you can alter and enhance the appearance and functionality of your 3D printed objects made from PLA, ABS, and PETG filaments.

Think about how your print will be used, what properties it needs, and what type of quality you require.

Conclusion

In the end, understanding the properties and characteristics of PLA, ABS, and PETG filaments, as well as their strengths, and limitations, will enable you to make informed decisions when selecting a filament for your next project. Think about factors like strength, durability, print quality, ease of use, and environmental impact, as well as the specific needs of your print applications. For example, a toy model will have different requirements than a functional prototype. Moreover, implementing best practices for printer settings, calibration, and post-processing techniques can significantly enhance the performance and appearance of your 3D printed objects. 

Frequently Asked Questions (FAQs)

Q: Can I mix different types of filaments in a single print?

A: While it is technically possible to mix different filament types in a single print using a dual-extrusion 3D printer, compatibility issues may arise due to varying printing temperatures and material properties. It is generally recommended to use compatible materials, such as PLA with PVA (a water-soluble support material), or materials specifically designed for multi-material printing.

Q: How should I store my 3D printing filaments?

A: Proper storage of 3D printing filaments is essential to maintain their quality and performance. Filaments should be stored in a cool, dry environment, away from direct sunlight. Airtight containers with desiccant packs can help prevent moisture absorption, which can negatively impact the filament's printing properties. You can read more about keeping filament dry here.

Q: Can I recycle or reuse failed prints and filament scraps?

A: Recycling 3D prints is not quite as straightforward as it may seem considering that most thermoplastics can be recycled. PLA is technically biodegradable, but requires specific industrial composting conditions to break down. ABS and PETG can be recycled but are not widely accepted at local recycling plants. There are desktop filament recycling systems, which grind up failed prints, melt them, and extrude them. The quality of their output can vary. It is also possible to buy professionally made filament derived from recycled materials.

Q: How can I improve bed adhesion for my prints?

A: Bed adhesion can be improved by using various techniques, depending on the type of filament. For PLA, a heated bed temperature of 50-60°C with blue painter's tape, BuildTak surfaces, or glue stick can provide good adhesion. ABS benefits from a higher bed temperature of 90-110°C and can be used with Kapton tape, ABS slurry, or specialized adhesion sheets. PETG adheres well to a bed temperature of 60-80°C with blue painter's tape, glue stick, or a clean glass surface. In all cases, ensuring the bed is level and clean is crucial for optimal adhesion.

References

[1] Samykano M, Selvamani SK, Kadirgama K, Ngui WK, Kanagaraj G, Sudhakar K. Mechanical property of FDM printed ABS: influence of printing parameters. The International Journal of Advanced Manufacturing Technology. 2019 Jun 19;102:2779-96. Available from:  https://link.springer.com/article/10.1007/s00170-019-03313-0 

[2] How to print with Ultimaker PLA [Internet]. Ultimaker. March 28, 2023. Available from: https://support.makerbot.com/s/article/1667337611872 

[3] 3D Printing Guide: Fillamentum PLA Extrafill [Internet]. Fillamentum. Available from:  https://fillamentum.com/wp-content/uploads/2020/10/FILL_Printing_Guide_PLA-Extrafill.pdf 

[4] How to print with Ultimaker ABS [Internet]. Ultimaker. January 27, 2023. Available from: https://support.makerbot.com/s/article/1667337602935

[5] PolyLite ABS [Internet]. Polymaker. Available from: https://us.polymaker.com/products/polylite-abs

[6] Prusament PETG Jet Black [Internet]. Prusa Research. Available from: https://www.prusa3d.com/product/prusament-petg-jet-black-2kg/#printing-setup

[7] How to print with Ultimaker PETG [Internet]. Ultimaker, January 27, 2023. Available from: https://support.makerbot.com/s/article/1667412428052#h_01F6S530F7ZZPSGDNC99BDRDM0