Glycol-Modified Polyethylene Terephthalate

PETG is PET with a glycol substitution in the polymer backbone. That substitution suppresses crystallization, so PETG stays amorphous regardless of wall thickness.

The practical consequence is that standard PET hazes when molded heavy-wall because it crystallizes, and PETG does not. When a cosmetic brief calls for a thick-wall bottle or jar with glass-like clarity, PETG is usually the correct specification and PET is usually not.

• Thick-wall clarity: Stays optically clear at wall sections where PET would go hazy.
• Impact strength: Better than both PET and acrylic, and notably more forgiving than acrylic in drop test.
• Decoration: Takes hot foil, silk screen, and pad printing well.
• Heat resistance: Lower than PET. Not a hot-fill resin.
• Cost: Meaningfully higher than PET. Specify it when the wall section requires it, not by default.

Premium cosmetic bottles and jars requiring a glass look at heavy wall. Airless system outer shells. Treatment packaging where impact resistance and clarity both matter.

Process: Injection molding and extrusion blow molding.

Shrinkage: 0.2-0.6%. Low and stable, which suits tight-tolerance decorated parts.

Drying: Less aggressive than PET's requirement but still required. Skipping it produces splay.

Watch for: Gate blush on high-gloss cosmetic parts. Slow the injection profile at gate fill and raise mold temperature to clear it.