PETG vs PLA Filament, What Are the Differences – PETG Properties, Uses & Printing Settings

PETG has emerged as a popular material in the 3D printing industry. This article provides an overview of the PETG material, focusing on its properties, applications, printing settings, and differences between PLA and PETG filament.

What Is PETG Material?

Polyethylene Terephthalate Glycol (PETG) is a versatile thermoplastic polyester that is a modified form of polyethylene terephthalate (PET). The addition of glycol in the polymer structure enhances its clarity and reduces temperature sensitivity, making it easier to extrude. PETG combines the desirable qualities of both ABS (acrylonitrile butadiene styrene) and PLA (polylactic acid), resulting in a material that exhibits high impact strength, excellent layer adhesion, and good printability.

Historically, PETG was developed through the pioneering efforts of British scientists James Dickson and John Whinfield in 1941. This material is particularly popular in the 3D printing community, especially for Fused Deposition Modeling (FDM) applications, due to its balanced mechanical properties and resistance to warping compared to other materials like ABS. Its chemical resistance and durability make it suitable for a variety of applications, including food-safe packaging and retail signage. Additionally, PETG offers good light diffusion, which is beneficial for products like lampshades and functional prototypes.

Moreover, PETG is available in several variations, including rPET (recycled PET), CPE (copolyester), and PETT (a less common variant that is not glycol-modified). Each variant shares similarities with PETG but comes with distinct properties that cater to different manufacturing needs. 

PETG 3D Printing Applications

• Industrial and Manufacturing: functional prototypes, end-use parts, mechanical components like gears and brackets, durable tools, jigs, fixtures for production, machine guards, safety barriers, and electronic enclosures.
• Consumer Products: household items, storage solutions, custom packaging, containers, consumer electronics casings, retail displays, signage, and lighting fixtures.
• Transportation: automotive interior/exterior components, drone parts, RC vehicle components, and custom brackets and accessories.
• Medical and Food: medical device components, dental aligners, equipment, food containers, and FDA-approved food-contact packaging applications.
• Creative and Educational fields: architectural models, teaching aids, artistic projects, sculptures, cosplay props, costume accessories, and display prototypes.
• Specialized Applications: aquarium components, ductwork, plumbing fittings, window replacements, transparent components, and custom vacuum forming and pressure forming parts.

PETG Printing Settings

To get the best possible PETG 3D printed parts, here are the recommended printing settings, including temperature, speed and more. 

Setting	Recommended Range
Nozzle Temperature	220–260 °C
First Layer Temperature	230 °C
Subsequent Layers Temperature	240–245 °C
Bed Temperature	65–90 °C
Print Speed	Up to 60 mm/s
Travel Speed	120 mm/s (double print speed)
Retraction Distance	3–7 mm (higher for Bowden)
Retraction Speed	20–25 mm/s
Fan Speed	30–60% (after first few layers)
Infill Density	20–30%
Support Z Distance	At least 2x layer height

Additional Considerations

• Build Surface: Use textured surfaces like PEI or blue tape to prevent over-adhesion.
• Cooling: Minimal cooling is generally better; enable fans after the first few layers.
• Filament Storage: Keep PETG dry to avoid moisture absorption.

PETG Filament Properties

PETG is an ideal 3D printing filament that combines the best characteristics of various materials. Its notable properties include flexibility, strength, and impact resistance, setting it apart from other common filaments like PLA and ABS.

• Strength and Durability: PETG is recognized for its robust nature, which makes it suitable for creating sturdy parts that can endure stress. It performs excellently under impact, often surpassing PLA and offering more flexibility than ABS, which can be brittle.
• Heat Resistance: While PETG is strong, it is more susceptible to scratches than PLA. It can withstand temperatures up to 70 °C, providing better thermal stability than PLA but not quite matching ABS.
• Moisture Resistance: PETG also offers good moisture resistance, so it is widely used in applications like vases or containers that hold liquids.
• Chemical Resistance: This filament exhibits high resistance to various chemicals, oils, and greases, ensuring longevity in diverse environments.
• Food Safety: Generally regarded as food-safe, it’s essential to verify that the specific PETG used meets food safety standards. Proper cleaning of printing equipment is crucial when producing kitchenware.
• Hygroscopic Nature: PETG tends to absorb moisture from the air, which can lead to printing issues. To avoid this, it should be stored in a dry environment and dried before use to ensure optimal print quality.
• Recyclability: Although PETG is recyclable, its chemical structure is different from PET, which complicates traditional recycling processes. Users are encouraged to utilize dedicated recycling services or consider purchasing recycled PETG filament to minimize waste.
• Printability: PETG is known for its ease of use, with excellent adhesion to print beds and minimal warping.
• Melting Point: The melting point of PETG generally falls between 220°C and 260°C (428°F – 500°F). This range can vary based on the specific formulation and crystallinity of the material.

PETG vs PLA Filament – Differences Between PLA and PETG

1. Printing Difficulty

PLA is widely regarded as one of the easiest filaments to print with, making it ideal for beginners. It requires lower extrusion temperatures (190-220°C), does not need a heated bed, and is less sensitive to environmental factors such as temperature fluctuations and slicer settings. PETG, on the other hand, requires higher extrusion temperatures (220-260°C) and a heated bed (75-90°C). PETG is also prone to stringing, where excess material creates wispy plastic strands, which can negatively impact the visual appearance of prints. While PETG has a steeper learning curve, with proper settings, it prints well and offers good thermal stability.

2. Strength

Is PETG stronger than PLA? PETG is not stronger than PLA in terms of tensile strength. PETG has better layer adhesion due to higher printing temperatures, making it less brittle and more resistant to impacts. It tends to bend rather than shatter under stress, which is a significant advantage in applications requiring durability. PLA, while having slightly higher tensile strength, is more brittle and prone to cracking or breaking under sudden forces. This makes PLA ideal for low-stress, decorative applications but unsuitable for functional parts that experience wear or impact.

3. Resistance to Environmental Factors

PETG is highly resistant to moisture, UV rays, and high temperatures, so it is suitable for outdoor applications and environments with harsh conditions. PLA, in contrast, is sensitive to heat and UV exposure. PLA parts can soften and deform at temperatures above 60-65°C and discolor with prolonged sun exposure. While PLA is biodegradable under industrial composting conditions, it is not suitable for outdoor use where durability is required.

4. Flexibility

PETG is more flexible than PLA, allowing it to withstand bending and impact forces without breaking. This flexibility makes PETG ideal for applications where parts may encounter physical stress. PLA is comparatively stiffer and less flexible, which can be advantageous for certain applications but also increases its likelihood of cracking or breaking under stress.

5. Temperature Resistance

PLA has a lower melting point and glass transition temperature (around 60-65°C), which limits its use in high-temperature environments. PETG, with a higher melting point and glass transition temperature (around 80-85°C), retains its shape and strength better in heat-intensive applications, such as outdoor use or functional prototypes.

6. Biodegradability

PLA is derived from renewable resources like corn starch and sugarcane, making it more sustainable than PETG, which is petroleum-based. PLA is biodegradable under industrial composting conditions, though it does not decompose easily in home composting setups. PETG is not biodegradable but is recyclable, with a more established recycling process compared to PLA. However, PETG’s production from non-renewable sources offsets some of its environmental benefits.

7. Post-Processing

PLA is easier to post-process than PETG. PLA supports can be easily removed, and it can be sanded, painted, or smoothed with relative ease. PETG, however, has stronger adhesion properties, making it harder to remove supports without damaging the print. PETG is easier to sand for a glossy finish but cannot be painted as easily as PLA. PETG’s transparency is an advantage in certain applications, such as food containers or industrial parts.

8. Applications

PLA is best suited for decorative items, prototypes, toys, and educational tools due to its ease of use and aesthetic quality. It is commonly used for low-stress applications where mechanical or environmental durability is not critical. PETG, on the other hand, is ideal for functional parts that may encounter stress, chemicals, water, or sunlight. It is often used in the food industry for containers and medical tools due to its durability and chemical resistance.

9. Cost

While PLA is often considered cheaper, the price difference between PLA and PETG is minimal. Both materials are available in a wide price range depending on quality and additives. PLA is typically slightly cheaper for hobbyist-grade filaments, but higher-end PLA and PETG filaments can be similarly priced, especially if enhanced with additives like carbon fiber.

PLA vs PETG Comparison Chart

Attribute	PETG	PLA
Ease of Printing	Moderate difficulty; requires higher temperature and heated bed. Prone to stringing and adhesion issues on the print bed.	Very easy; prints at a lower temperature, and no heated bed required. Less sensitive to environmental factors and slicer settings.
Flexibility	Flexible and impact-resistant; bends before breaking.	Stiff but brittle; cracks or shatters under stress or impact.
Strength	Lower tensile strength.	Slightly higher tensile strength but is brittle.
Temperature Resistance	Higher resistance (up to 80–85°C); retains shape in heat-intensive applications (e.g., outdoor use).	Lower resistance (up to 60–65°C); deforms under heat and prolonged exposure to sunlight.
UV/Weather Resistance	Excellent; resistant to UV rays, water, and harsh environments. Suitable for outdoor use.	Poor; degrades and discolors with UV exposure and warps in warm conditions.
Moisture Resistance	Resistant to water; ideal for items exposed to moisture or submerged in water.	Poor; absorbs water over time, which can degrade part quality.
Chemical Resistance	Resistant to many chemicals, including oils and some solvents (but not acetone).	Poor; vulnerable to chemicals, including water, oils, and solvents.
Transparency	Can be printed with transparent or translucent properties; great for applications requiring visibility.	Limited transparency options; are usually more opaque.
Biodegradability	Non-biodegradable.	Biodegradable under industrial composting conditions, but home composting is ineffective.
Post-Processing	Moderate difficulty; sanding for a glossy finish is easier, but painting is difficult. Support removal can damage parts due to strong adhesion.	Easier to post-process; supports are easier to remove, and surfaces can be sanded, painted, or chemically smoothed with ease.
Odor During Printing	Odorless or mild plastic smell.	Slightly sweet smell during printing due to its plant-based origin.
Applications	Functional parts, food-safe containers, outdoor items, protective casings, and mechanical parts.	Decorative items, toys, prototypes, low-stress applications, and educational tools.
Cost	$15–$25 per kg; slightly higher for specialty PETG filaments like carbon fiber-reinforced variants.	$12–$20 per kg; low-end PLA is cheaper, but high-end PLA filaments with additives can be similarly priced to PETG.
Printing Temperature	220–260°C (extrusion); requires a heated bed at 75–90°C.	190–220°C (extrusion); no heated bed required (optional 50–60°C for better adhesion).
Stringing/Oozing	High tendency; requires careful tuning of retraction settings.	Low tendency; easier to achieve clean prints without stringing.
Durability	High; resistant to wear, fatigue, and environmental exposure.	Low; fragile and prone to cracking over time.
Cosmetic Quality	Fair; can achieve a glossy finish with sanding. Often shows stringing, making it less visually appealing.	Excellent; smooth and clean prints with minimal effort.
Recyclability	100% recyclable, but considered a contaminant in standard PET recycling.	Recyclable but less commonly accepted in traditional recycling streams.
Food Safety	Food-safe options are available; check for FDA-approved filaments. Good for food storage applications.	Food-safe options available; more limited in applications due to water absorption and lower durability.
Weight	Heavier than PLA due to its higher density.	Lightweight; less dense than PETG, making it ideal for prototypes and low-weight applications.
Surface Finish Options	Glossy finish achievable with post-processing; good for semi-transparent prints.	Matte or glossy finish achievable, depending on filament type. Easier to achieve smooth surfaces without heavy post-processing.
Warping/Cracking	Moderate; requires a heated bed and proper cooling to prevent warping or cracking during printing.	Low; minimal warping or cracking even without a heated bed.
Tensile Strength (Yield)	~50 MPa.	~57.4 MPa.
Elongation at Break	~130%; allows significant bending and stretching without breaking.	1.9–4%; very little flexibility before breaking.
Heat Bed Requirement	Required; prints adhere better with a heated bed (75–90°C).	Not required; optional heated bed at 50–60°C for better adhesion and surface finish.
Safety	Non-toxic during printing; minimal fumes.	Non-toxic during printing; minimal fumes, but prolonged exposure may release small amounts of lactic acid.
Scratch Resistance	Poor; scratches easily due to softer surface properties.	Better scratch resistance compared to PETG but still not ideal for wear-heavy applications.
Impact Resistance	Good; absorbs impact well due to flexibility.	Poor; brittle and shatters under impact.