September 27, 2020
petg filament 3d printing guide cover

The Complete PETG Filament 3D Printing Guide

PETG is a great all-around filament for 3D printing almost anything, offering a mix of the benefits offered by both PLA and ABS without any significant downsides. It’s strong, somewhat flexible, stands up well to heat, is very impact resistant without breaking, and offers a smooth, glossy finish. And all this, while still able to be printed on budget 3D printers costing under $1,000.

PETG is a modified version of PET (polyethylene terephthalate) mixed with glycol which makes it less brittle, clearer, and more durable and impact resistant. Standard PET is extremely widely used: most water bottles are made from PET, so it makes sense than an enhanced PET would be suitable for 3D printing. PETG has an 80C glass transition temperature, which is less than ABS (105C) but more than PLA (60-65C), with printed parts able to handle any normal activities and heats without deforming.

  • We also have another article explaining the differences between PLA vs PETG.

PETG melting point & print settings

PETG is generally 3D printed at an extruder temperature of between 220C and 260C. While a heated bed is not absolutely required, we still recommend using one to prevent warping. A heated bed temperature of 70-90C usually works well, though some makers use lower temperatures without issue.

Experiment to find the best printing temperature for your PETG and 3D printer. Try 230C and increase the temperature from there if you see too much stringing in your print.

Whereas a cooling fan is not necessary for filaments like Nylon and ABS, it is advantageous to use a cooling fan with PETG. Ideally, optimize your settings to print the first few layers without the cooling fan, and then turn it on fully for subsequent layers. This improves bed adhesion for the first layers, with the fan helping with precise details and reducing stringing on the following layers.

Unlike with ABS, an enclosure or closed chamber is not required when printing PETG. If you use a 3D printer with a closed print chamber or with an enclosure, consider leaving the door or top open.

For a build surface on your print bed, blue painter’s tape works well, as does using glue stick or hairspray. Be mindful of glass print beds as PETG’s excellent layer adhesion can make it extremely difficult to remove after printing, and can take bits of your print platform with it when removing it.

petg 3d printed translucent parts
PETG offers a glossy, translucent effect on parts that makes prints look great.

How much does PETG filament cost?

PETG is generally slightly more expensive than PLA and ABS, but still reasonably priced. Whereas the starting prices of PLA are around $20, PETG starts at around $24. Higher quality, industrial standard PETG filaments cost considerably more, such as Matterhackers’ PRO series PETG which starts at around $55.

Some sites offer PETG pellets, for those who want to save some money on PETG filament, and who have the equipment and don’t mind spending the extra time turning the pellets into filament. You can also dye it during this process for custom PETG colors and blends.

Best PETG Filament

For every day, entry level 3D printer hobbyists who want to experiment and have fun, basic low cost PETG will suffice. Those looking to make high quality parts with rapid prototyping may instead be drawn towards industrial 3D printer PETG filament, costing more.

Online stores we recommend with great PETG filament selections include:

petg filament spools
PETG comes in a variety of colors.

Advantages and Disadvantages of PETG

Advantages of PETG Filament

  • Great middle-ground between PLA and ABS: PETG is stronger and can handle higher temperatures than PLA, while warping less than ABS.
  • Excellent layer adhesion without much warping: PETG’s stickiness gives it great adhesion to the print bed, leading to strong, durable parts. This makes PETG a great option for long and thin parts that are very difficult to print using filaments like ABS.
  • Good surface finish: PETG prints come out glittery and glossy, with a translucent, radiant finish. Though not to everyone’s tastes, many enjoy the finish they get from PETG 3D printing.
  • Odorless: unlike ABS, PETG does not create bad smells from fumes while 3D printing.
  • Many color options: like ABS and PLA, there are many options to choose from with PETG, so you’ll never struggle to find the blend you want for a particular project.

Disadvantages of PETG filament

  • Poor for supports or bridges: the excellent layer adhesion comes at a cost: PETG supports can stick too well, creating difficult-to-remove supports that can leave marks on the part. If you have a dual extruder 3D printer, consider printing a different support material like PLA that is easier to remove.
  • Can string, worsening surface finish: make sure to fix your retraction settings as otherwise strings or hairs can affect the surface finish of your prints, and are generally annoying. Research good 3D slicer settings for your desired results.
  • Bad scratch resistance compared with ABS: the glycol that enhances PETG from PET in so many ways makes it less scratch resistant, so over time parts can wear down and look less aesthetically pleasing.
  • Difficult post-processing: the chemical resistance is also an advantage, but means PETG can’t be acetone polished like ABS can for a better surface finish. PETG’s natural glossy finish means this isn’t a big downside however, and it can still be sanded.

How to get the best results from PETG 3D printing

petg 3d printing best practices
  • Precise, correct print settings: find the best retraction speed and distance settings that minimize stringing, and the best extruder and heated bed (if using) temperatures. Also consider turning off your cooling fan for the first few layers to prevent warping, then turn the fan on for the following layers.
  • Use a good build surface: Standard painter’s tape is considered a great option for PETG 3D printing, among options like hairspray and glue stick.
  • Use a dual extruder with a different filament for supports: as it sticks so well, PETG is notoriously bad for supports. If you have a dual extruder 3D printer, consider printing supports in PLA or a specialized support filament (that works well with PETG) that can be easily removed or dissolved after printing.

PETG Applications

PETG is considered food and drink safe, and is often used for waterproof parts and parts that will come into contact with food. Additionally, because of its great bed adhesion and very little warping, long and flat parts are often best 3D printed in PETG, such as mechanical parts.

Owing to PETG’s strong impact resistance, durability and density, PETG is the filament of choice for many makers creating custom parts for drone projects or other remote controlled electronic experiments. Additionally, 3D printer parts are sometimes made from PETG, among other protective casings for electronics and motors as PETG can handle heat reasonably well.

PETG’s great, partially see-through finish also makes it a good candidate for some forms of jewelry. Homemade 3D printed jewelry designs can look great in PETG. Anything that needs to be translucent comes out great with PETG.

petg 3d printer parts
Replacement parts for 3D printers are often printed from PETG, such as those for the Prusa i3.

How to Store PETG

PETG is slightly hygroscopic, meaning it absorbs small amounts of moisture from the air which worsens the print quality of PETG parts over time, making them more brittle and bubbly. It is recommended to keep all filament in a good filament storage container or other protector, or at least in a dry part of the room.

You can also dry “wet” PETG with a filament dryer. This helps remove most of the moisture and avoids most of the downsides that occur if you leave filament out for too long.

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