PLA With PETG Core Filament Put to the Test

Sometimes you see an FDM filament pop up that makes you do a triple-take because it doesn’t seem to make a lot of sense. This is the case with a …read more

Jun 26, 2025 - 19:10

PLA With PETG Core Filament Put to the Test

The Stronghero 3D hybrid PLA PETG filament, with visible PETG core. (Credit: My Tech Fun, YouTube)

Sometimes you see an FDM filament pop up that makes you do a triple-take because it doesn’t seem to make a lot of sense. This is the case with a hybrid PLA/PETG filament by Stronghero 3D that features a PETG core. This filament also intrigued [Dr. Igor Gaspar] who imported a spool from the US to have a poke at it to see why you’d want to combine these two filament materials.

According to the manufacturer, the PLA outside makes up 60% of the filament, with the rest being the PETG core. The PLA is supposed to shield the PETG from moisture, while adding more strength and weather resistance to the PLA after printing. Another interesting aspect is the multi-color look that this creates, and which [Igor]’s prints totally show. Finding the right temperatures for the bed and extruder was a challenge and took multiple tries with the Bambu Lab P1P including bed adhesion troubles.

As for the actual properties of this filament, the layer adhesion test showed it to be significantly worse than plain PLA or PETG when printed at extruder temperatures from 225 °C to 245 °C. When the shear stress is put on the material instead of the layer adhesion, the results are much better, while torque resistance is better than plain PETG. This is a pattern that repeats across impact and other tests, with PETG more brittle. Thermal deformation temperature is, unsurprisingly, between both materials, making this filament mostly a curiosity unless its properties work much better for your use case than a non-hybrid filament.