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Last updated 10 months ago
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Basic info

PETG is one of the most easily printable materials, it is inexpensive and suitable for beginners. Relatively high tenacity and temperature resistance make it suitable for printing technical parts (for example parts of our printers).
 
Recommended nozzle temperature: 230 °C for the first layer, 240 °C for the other layers
 
Recommended bed temperature: 85 °C for the first layer, 90 °C for the other layers
 
Heatbed: Using powder-coated TXT or satin sheet is highly recommended. Printing on smooth PEI surface might damage the sheet.

Description

PETG (Polyethylene Terephthalate modified with Glycol) is a commonly used technical material, popular among 3D printer users for its low price and good printability. It’s tenacious, with good temperature resistance; PETG is most commonly used for printing various mechanical parts, holders, clamps, and waterproof parts (thanks to great layer adhesion).

PETG has a glossy surface, adheres greatly to a print sheet, and does not shrink or warp (it has very little thermal expansion), therefore it’s suitable for printing large models. Plus, its high tenacity and flexibility often prevent it from breaking. Due to good temperature resistance, PETG parts are suitable both for interior and most exterior use (with temperatures below 80 °C). Parts of our printers are made of PETG!

The letter G in PETG means that it’s modified with glycol during the manufacturing process. Glycol makes PET less brittle, easier to print, and more transparent for translucent prints. Of course, you can print also with PET filaments without glycol. However, printing with only PET is challenging and does not offer any advantage whatsoever.

Even though PETG in itself may be considered food-safe, it consists of layers, as every 3D print, in which bacteria can grow over time. You can prevent this by applying a food-safe(epoxy) coating. Also, a stainless-steel nozzle should be used for if food is the intended application.

Although PETG is frequently used in food industry and is considered food-safe, we do not recommend it (or any other filament) for printing dishes or other stuff that comes into direct contact with food. The main reason is tiny print layer surface grooves that can support numerous bacterial colonies. But if you still want 3D printed dishes, we suggest applying a special layer that seals the surface (food-safe coating) and printing with a clean steel nozzle.

Some of the manufacturers enrich PETG with various additives and sell these materials under different names. For example, Spoolworks EDGE by E3D is modified PET/Copolyester Blend with additives. The goal is to acquire better visual qualities, surface and layer adhesion, etc.

To compare supported material properties, see our material table.

Pros

Cons

✔ Easy to print

✖ Possibility of stringing

✔ Good layer adhesion

✖ Poor bridging and overhangs

✔ Tough and durable

✖ Not great for printing detailed parts

✔ Low warping

✖ Bonds strongly to the print surface

✔ High temperature-resistance

✖ Soluble in dangerous chemicals

✔ Water and humidity resistant

✖ Supports are hard to remove

Best use

PETG is used universally but is especially suitable for mechanical parts for both indoor and outdoor use. We use PETG to print parts for our printers! Plastic bottles are also made from this kind of material.

Tips for successful printing

Temperature settings and cooling

Unlike PLA, PETG requires a heated bed (85 °C). Its bridging- and overhang-behavior is usually worse, plus it is prone to stringing. Stringing can be moderated with higher retractions and lower nozzle temperature, but we suggest using the PrusaSlicer profiles that should work fine. It’s important to cool the PETG print - this helps to keep the model detailed and prevents stringing and oozing. But if you want the model to be as tough as possible, try to turn off the print fan. Higher filament temperature improves merging between layers which leads to better mechanical resistance. Otherwise, we recommend printing the first few layers with the print fan off to prevent deformation, then with the fan running at half its power.

Do not print on the smooth PEI sheet as the adhesion may be too strong!

Print surface preparation

Make sure the print surface is clean, as described in our dedicated article. It is advisable to use one of the powder-coated print sheets. Do not print on the smooth PEI sheet as the adhesion may be too strong! If you decide to use the smooth PEI sheet anyway, apply a glue stick on it before printing.

Adding more perimeters for more solid parts

If you want to print truly solid parts, try to increase the number of perimeters instead of adding more infill.

Postprocessing

PETG can be easily sanded both dry and wet.

Dissolving PETG

Dissolving and smoothing PETG is possible only in a laboratory by skilled lab workers using dangerous chemicals (Dichloromethane).

Sample prints

MMU (Multi-Material Unit)Electronics cover and other printer parts
UkuleleVarious mechanical parts
Electronic partsBoxes and organizers
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