Master PETG Print Settings: Unlock Flawless 3D Prints in Minutes

If you are a 3D printing enthusiast, most likely the first two filaments to ring in your head are PLA and ABS, being the most common types of filaments available. However, if you are looking for the one that can offer you the best benefits of the two in terms of strength, durability, and ease of use, then I need to introduce you to PETG, or as its chemical name goes: Polyethylene Terephthalate Glycol. It amalgamates the strength of ABS with the flexibility and printability of PLA, making it perfect for functional parts that can take a beating.

In this guide, we will be doing an in-depth study into all the ins and outs of 3D printing with PETG-from the basic knowledge down to optimizing the prints and avoiding pitfalls-to get the full throttle with this very versatile filament.

Let's get started!

What is PETG Filament?

Before we get down to the juicy details, let's step back a second and talk about what it actually is. PETG is a strong thermoplastic polymer loved for its strength, resistance to chemicals, and for having excellent layer adhesion. Among many kinds of filaments out there, one factor that sets it apart is its partial transparency. If you've ever wondered what those crystal-clear plastic water bottles were made from, it's actually PET-in essence, the elder sibling of PETG. Still, while PET sees its use in industry, it's far from being perfect for 3D printing. For one, PET is brittle and has a high melting point, which doesn't make it the easiest material to manipulate. That's where the "G" comes in.

 

This is achieved by adding glycol to the mixture, which allows PETG to be far more flexible and at a much-reduced printing temperature. The result is a filament that's tougher than PLA, yet a great deal easier to print with than ABS. This flexibility makes PETG one of the go-to materials for things like printing snap-fit parts, enclosures, or even tools. Whether it is for printing robust mechanical parts or for something as simple as a vase, it is worth trying with PETG.

Technical Properties of PETG:

• Tensile Strength: Around 55-70 MPa, making it comparable to ABS in terms of toughness.
• Elongation at Break: PETG offers an elongation at break of around 20-25%, which means it is much less brittle than PLA.
• Glass Transition Temperature: PETG has a glass transition temperature around 80°C, meaning it maintains strength and stiffness at moderately high temperatures.
• Melting Temperature: Around 260°C, though printing temperature is lower.

Why use PETG for 3D printing?

So now that we know what PETG is, why would you choose it over other filaments, such as PLA or ABS? Well, there are a number of reasons. First of all, PETG is very easy to print. Unlike ABS, which tends to warp and even crack given half a chance (when exposed to changes in the surrounding temperature, while printing), PETG sticks down to the print bed without too many problems. It's not just easier to print than ABS; it's often easier than PLA, too, depending on your setup.

If you want to read a detailed comparison between PETG and ABS filament, we've got you covered. Check out our article: PETG vs ABS: A Comprehensive Guide.

And for a comparison between PETG and PLA, check out: What is PETG vs PLA for 3D Printing

One of the great things about PETG is just how robust it is. It can take a beating and keep on ticking. If you need to create parts that will be used extensively, PETG is a great choice. It really doesn't break easily. When PETG does eventually break, it bends and flexes first, further helping your parts last longer. That makes it ideal for functional parts such as custom tools, enclosures, or anything else that would incur a great deal of mechanical stress. Another great thing about PETG is that it resists most chemicals, making it a great choice for those parts that could be exposed to oils, acids, or any other kind of harmful material. It is very strong outdoors and does not degrade quickly when exposed to UV light-yet another plus when comparing it to PLA.

Another benefit is that PETG is safe for food. If you want to print containers or tools, you don’t need to worry about harmful materials getting into your food.

However, 3D-printed parts can hold bacteria in the tiny gaps between layers. So, be careful if you’re printing items related to food by covering surfaces with coatings that are safe for food.

Another aesthetically pleasing option is PETG. The filament itself is clear, and it makes for shiny, smooth prints. It should be your go-to material if the look of your projects plays a big part. You can print with it a clear vase or a lamp shade that will allow light to shine through.

Here is one more: unlike ABS, PETG does not smell nor produce any strong fumes while printing. You can print this material in your home or workspace without a special enclosure or filter system.

The Problems of Printing PETG

No filament is perfect, of course, and PETG has its own set of problems. Let's talk about some issues you may find when printing with it.

The most significant problem that people encounter with PETG has to do with stringing. It tends to leak from the nozzle, and these leaks can create thin hair-like strands of filament between different parts of your print. This makes your print messy, but fortunately, you can reduce this a little with adjustments. Stringing is when the nozzle drips filament while moving between parts of the print. Playing around with retraction settings and print temperature will help. Retract distance for Bowden setups: 6-8 mm, for direct drive: 2-3 mm. For retraction speed, 25-30 mm/s generally works fine to reduce stringing.

Another thing to keep in mind is that PETG prints at a higher temperature than PLA. We’re talking anywhere between 230°C and 260°C, which is well within the range of most desktop printers but can be hard on your hot end if you’re using a PTFE-lined setup. Printing at these high temperatures for long periods can cause the PTFE tube to degrade, leading to clogs or extrusion issues. That is why many people suggest printing with an all-metal hot end when printing with PETG. If not, then it is not considered to be a problem, but yes, it will help your printer last longer.

PETG is also hygroscopic, meaning it absorbs moisture from the air like a sponge. If your filament becomes too wet, you’ll notice blobs, rough surface finishes, and even a noticeable loss of strength. It’s crucial to store PETG in an airtight container with desiccant to keep it dry, or invest in a filament dryer to remove any absorbed moisture before printing.

Preparing Your 3D Printer for PETG

For setting up your 3D printer for PETG filament, there are a few things to be aware of to get clean, strong, and smooth prints. In fact, printing with PETG is somewhat different compared to PLA or ABS; thus, tweaking your setup can make all the difference.

Now, let's look at what you need to prepare your printer for PETG.

Printer Compatibility

Before printing with that spool of PETG, you really should check to see if your printer can support this filament. In comparison to PLA, printing PETG requires higher temperatures; it means checking that the hot end on your printer can at least reach 230°C, although it is better if it can easily go up to 260°C. Most regular desktop 3D printers without extra modifications will be able to use this filament.

In addition to the hot end temperature, you’ll need a heated bed. PETG’s strong adhesion properties are a double-edged sword—it sticks strongly but can also warp or lift if the bed temperature isn’t just right. Set the bed temperature between 70-90°C for the best results. The heated bed helps maintain consistent adhesion throughout the print, preventing the dreaded corner warping that can ruin your otherwise perfect print.

One highly recommended option for printing PETG is the Kingroon KLP1 CoreXY Printer. This printer is ideal for both hobbyists and professionals who want a reliable machine that can print with speed, precision, and consistency. Capable of reaching print speeds of up to 500mm/s, it ensures fast, high-quality results without compromising on accuracy. Its acceleration of 10000mm/s² helps reduce print times, and its advanced Klipper firmware (pre-installed) eliminates the need for a separate Raspberry Pi while enhancing overall performance.

The Kingroon KLP1’s all-metal hot end and powerful extruder, with a gear ratio of 5:1 or 9.5:1, provide excellent control over PETG, preventing common issues like clogging or inconsistent extrusion. Additionally, its auto bed leveling feature ensures perfect first-layer adhesion, which is essential for avoiding problems like warping or lifting. The printer’s vibration compensation system reduces errors at high speeds, making it perfect for printing larger, more complex PETG models.

Along with PETG, the Kingroon KLP1 can handle a wide variety of materials, including TPU, PLA, ABS, and nylon, offering great versatility. To explore more about this robust 3D printer, check out the Kingroon KLP1 CoreXY Printer.

Additionally, Kingroon offers a great selection of filaments, including PETG, making it a one-stop shop for all your 3D printing needs.

Bed Surface Preparation

One of the most dramatic differences between PETG and other materials, such as PLA, involves adherence to the print bed. It really sticks-often so well that the printed part is not easy to remove from the bed. To help with this, it is important to choose the right bed surface.

For most of the PETG prints, Glass, PEI sheets, or BuildTak are good surfaces to print on, but since PETG can stick pretty well, it is smart to use something to help in sticking. Either a glue stick or Magigoo applied on top of the surface will facilitate an easy sticking job for PETG when printing and taking it off once the print is done. This glue acts as an intervening barrier between the PETG and the bed surface. The filament doesn't allow it to stick too strongly to the bed. That is pretty useful when printing on glass or PEI sheets because too strong sticking could harm the bed.

Bed Leveling and Nozzle Height

Having a good print in PETG involves proper bed leveling and correct nozzle height. Because PETG is a very sticky material, it is important that your bed is perfectly level to get the first layer just right. You may have uneven sticking if your bed is not level; this can cause warping or even failed prints.

Manually leveling the bed using a piece of paper is a tried-and-true method, but if your printer has an automatic bed leveling sensor, it’s even easier to ensure a consistent gap between the nozzle and the print bed. Aim for a nozzle gap that’s slightly larger than what you’d use for PLA—about 0.1 mm. This will make the filament almost uninstructively move out of the nozzle without getting pushed down too much, which can make it stick to the bed too hard.

If you own a Kingroon KP3S Pro V2 or KLP1 3D printer and need to calibrate the bed leveling, you can follow our simple guide here: Bed Leveling Tutorial for the KINGROON KP3S Pro V2 and KLP1.

Optimizing Printer Settings for PETG

Nozzle Temperature

PETG loves heat. To get optimal layer adhesion, you’ll want to print PETG at a temperature between 230°C and 260°C. Every filament brand is a little different, so it’s a good idea to print a temperature tower to dial in the perfect temp for your specific spool. Printing too hot will lead to stringing and oozing, while printing too cold will result in poor layer adhesion.

Bed Temperature

A heated bed is quite necessary when printing with PETG. Set the bed temperature anywhere between 70°C to 90°C, to be precise, to prevent warping and to make sure that the first layer adheres well. PETG doesn't shrink much, so it works great for large prints, but without a heated bed, corners may lift or your print could come off halfway through.

Cooling Fan Settings

With most prints, it is a good idea to have the cooling fan on while printing PETG. This will help cool the filament faster, especially for bridges and overhangs. However, for the strongest print with the best layer sticking, try turning the fan off. Without the cooling fan, the layers will stick with one another better and give you a much stronger, longer lasting print.

Resolving Common Issues with PETG

Stringing and Oozing

Stringing is a major problem for many users of PETG. This occurs when thin strands of filament stretch between parts of the print, resulting in little strands that can lower the quality of the print. In order to reduce stringing, first ensure that you have the right retraction settings. For PETG, a good starting point for retraction distances should be around 6-8 mm for Bowden extruders and 2-3 mm in Direct drive systems. and retraction speeds of 25-30 mm/s. Also, if the problem of stringing persists, try lowering the print temperature a bit.

 

For more detailed tips on preventing stringing and blobs, check out this helpful guide: Tips to Prevent 3D Print Stringing & Blobs.

Warping and Lifting

Warping can occur if your bed adhesion is not good enough. Make sure your bed temperature is in the right range (70-90°C) and that the bed is leveled correctly. Using brims or rafts can also help stop the corners from lifting, especially on larger prints.

Nozzle blockages and jams

PETG is a hygroscopic material which absorbs moisture from the air. Poor drying before use will cause blockages and nozzle jams. If you notice bubbling or uneven lines during printing, it means your filament has possibly absorbed moisture. You should dry it either in a filament dryer or in an oven at 50-60°C for a few hours before printing.

Post-Processing PETG

There are several ways to clean and make your PETG print nice when it is done.

Sanding and Polishing

Sanding is an easy way to smoothen out surface imperfections on PETG prints. Due to its high glass transition temperature at about 85°C, PETG will not easily melt due to friction caused by sandpaper. Progress from using 100-grit sandpaper to higher levels of fineness, such as 1000-grit, if that smooth finish is really needed. Wet sanding does a fine job for getting a glossy surface on PETG prints.

Heat Gun

A heat gun will save you from sanding and can make the surface of your prints smooth. You just heat the surface carefully, thereby gluing the layers together and removing minor imperfections. Just be careful not to overheat-that's the last thing you want or need for your print, distorting its shape or causing it to melt completely.

FAQs

1. What is the ideal printing temperature for PETG?

PETG prints best at temperatures between 230°C and 260°C. Every filament brand may vary slightly, so it’s recommended to print a temperature tower to find the optimal temperature for your specific spool. Too high of a temperature can lead to stringing, while too low can cause poor layer adhesion.

2. Do I need a heated bed for PETG?

Yes, a heated bed is essential for PETG. The recommended bed temperature is between 70°C and 90°C. A heated bed helps prevent warping and ensures the first layer sticks properly to the surface, providing consistent adhesion throughout the print.

3. How can I prevent stringing when printing PETG?

Stringing can be reduced by adjusting retraction settings and lowering the print temperature. For retraction, a distance of 6-8 mm for Bowden extruders or 2-3 mm for direct drive systems, paired with a speed of 25-30 mm/s, works well for minimizing stringing.

4. What is PETG filament good for?

PETG filament is excellent for creating strong, durable objects with a good balance of flexibility and rigidity. It's ideal for functional parts, like mechanical components and enclosures, due to its impact resistance and heat tolerance. PETG is also easy to print, making it a popular choice for both beginners and experienced users.

5. Is PETG really better than PLA?

Yes, PETG is stronger and more heat-resistant than PLA, but it also has some weaknesses compared to PLA. PETG is more durable, heat-resistant, and flexible, making it ideal for functional parts and outdoor use. PLA is easier to print and biodegradable, perfect for beginners and decorative items. The choice depends on your project needs.

Last Thoughts

PETG is a fantastic material for 3D printing, offering the best of both worlds in terms of strength and ease of use. It’s a great alternative to ABS if you’re looking for something durable without the headaches of warping and toxic fumes, and it’s an excellent step up from PLA for more functional, load-bearing parts.

A little tugging on the printer settings, some patience, and you'll be printing great PETG in no time. Keep your filament dry, dial in your retractions, and remember that heated bed to eliminate warping. Whether you're printing for strength, aesthetics, or a mix of both, PETG is a reliable choice that will take your projects to the next level.

So, start printing, and have fun with the amazing flexibility of PETG!