PLA and PETG Glass Transition Temperature (3D Printing)

Well, if you have just entered the field of 3D printing or are just looking to brush up on your facts regarding 3D printing materials, especially about PLA/PETG glass transition temperature, you have come to the right place!

Messing up on the glass transition temperatures can be proven to be disadvantageous, so it’s better to keep them right before you end up losing the expensive material, your time, and your effort. 

So, do not let the materials deform by not missing out on the article. Scroll till the end to not just learn about glass transition temperatures but also brush up on your knowledge. Also, here’s an in-advance welcome to all the beginners because hopeful the article will prove to be the one-stop solution for you! 

3D Printing Filaments – PLA and PETG

Now, there are different kinds of 3D printing materials, and which one is chosen for which purpose depends. 

For professional purposes, it is advised to go ahead with a suitable filament by understanding its purpose, characteristics, and so on. But you won’t have to think much if you’re just printing something for fun. You can just go ahead with a filament that is easy to print. 

PLA and PETG are the filaments that are pretty popular in the field of 3D printing, especially for the ones that do 3D printing as a hobby. PLA is the short form of polylactic acid, and PETG is the short form of Polyethylene Terephthalate Glycol-Modified. 

Where on the one hand, PLA is one of the easiest filaments to print with because the melting temperature of PLA is 155°C which is low and isn’t very sensitive to the surrounding environment. The benefit of PLA is that it has food-safety properties. The cons of using PLA are that it can’t handle high temperatures and UV rays, so not a good choice for printing outdoor items.

PETG is another commonly used filament, mostly in water bottles and containers. The melting point of PETG is 210°C, and this material is more durable and strong, along with being resistant to high temperatures and UV rays. The benefit here is that it isn’t very harmful to the environment.

What is Glass Transition Temperature?

Temperatures are different. When talking about the filaments, make sure you do not get confused between the melting point temperature of a filament and the glass transition temperature of a filament. 

The glass transition temperature is the point where the material starts losing its complete solid form and enters a dense state. It determines the heat resistance of the object. Understanding the glass transition temperature is important because it lets you know how much you can heat the material before it deforms and loses its strength.

Effects of Glass Transition Temperature on PLA and PETG

As mentioned above, PLA and PETG are famous and commonly used. But they have different characteristics, and hence there would be a different PLA glass transition temperature and a different PETG glass transition temperature.

To begin with, the PLA glass transition temperature is not very high and ranges between 55 to 60 degrees Celcius because the material is sensitive to high temperatures and UV rays.

Moving on to the PETG, the PETG glass transition temperature would be higher than PLA as its characteristics include more durability and strength, requiring a higher temperature. So its glass transition temperature would be between 80 to 85 degrees Celcius

This slight difference here is because PETG of different brands might show some slight differences so that the temperatures might vary between 1 to 5 degrees Celcius. What you can do here is, take a small amount of PETG and experiment with it; this would let you know what exact temperature could be chosen for the process.

What happens when the glass transition temperature is too low or too high?

You might definitely wonder what happens if the temperature is too low or too high. Right? Well, suppose the bed temperature is kept too low compared to the glass transition temperature of the particular material. In that case, adhesion issues will occur, and the filament will end up staying rigid.

Whereas if the temperature is kept too high, it will cause warping and lead to the filament becoming deformed. 

Glass transition temperatures for other materials:

Here are a few additional glass transition temperatures that can be added to your list,

  • TPU Glass Transition: 60 degrees Celsius
  • Glass transition temperature of ABS is 105 degrees Celsius
  • Nylon Glass Transition: From 70 to 75 degrees Celsius
  • Polycarbonate Glass Transition: From 145 up to 150 degrees Celsius


It is quite evident how the wrong temperature in any sense, if lower or higher, can affect the material wrongly and ruin the entire project, so it is advised to follow the temperatures precautionary and avoid any mistake possible at your level.

Hope that the article helped and that it becomes your referring guide when you start making your 3D prints.