“PET filament”, “PETg filament”, “PETG filament” “PET-G filament” – all of these are common names used in 3D printing. Whilst at first glance “PET” and “PETg” may appear to be the same material, their (incorrect) interchangeable use by material companies and 3D printer users alike can be misleading. This article explains the difference between the two filament materials and summarises the benefits and disadvantages of both. 

PET (Polyethylene terephthalate)

  • Higher working temperature
  • More rigid
  • More brittle

If you are looking to get a print out that is rather rigid, PET 3D printer filament is the right material for this occasion. It has a slightly higher working temperature compared to PETG and is rigid, much like PLA. Although prints made with PET are hard, they are prone to be broken easily. So be aware if you know that your part is going to be subjected to a considerable amount of stress as the plastic would break rather abruptly, with not much sign of plastic deformation.

Did you know? Our ONE PET 3D Printer filament contains 100% recycled content made from waste PET plastic bottles.


PETg (Polyethylene Terephthalate Glycol)

  • Has glycol added (hence the “g”)
  • Slightly more flexible
  • Greater impact resistance
  • Absorbs more moisture (Dehydrating PETg before use is a good idea)

PETg can simply be thought of as PET with glycol added. The addition of glycol allows the material to be slightly more flexible, but not as much as TPU or TPE. Having a little more flexibility allows parts to have a greater tolerance to impact compared to PET.  Be careful of how you store your PETG as the addition of glycol means that the material absorbs more moisture. Ensure that you keep your PETg 3D printer filament in an airtight environment or dehydrate it before use.

See our PETg 3D printer filament range here.

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Technical Data Comparison















Whilst PET and PETg 3D printer filament may sound as though they are very similar, it is important to remember that they offer different properties – which should be compared when choosing the most appropriate material for your project.

To summarise – where our regular PETg has a better impact resistance, ONE PET boasts superior technical properties such as tensile strength, not to mention the environmental benefit of 100% recycled content. 

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