PETG

PETG (glycol-modified PET) is the same plastic as food bottles, in a printable form. It is the sweet spot: nearly as easy as PLA, but the part is tougher, water-resistant, holds up to ~70 °C, and flexes instead of snapping. The surface comes out glossy and often semi-transparent.

What it is good for

• Functional parts: brackets, holders, enclosures
• Items in contact with water and household chemicals
• Transparent and translucent models, shades, vases
• Parts that should flex slightly rather than break

Where NOT to use it

• Small, intricate fine-detail parts — PETG loves to string
• Supports on the model itself — PETG bonds to itself too well to peel cleanly
• Parts above ~75 °C — use ABS/ASA instead
• When you need a perfectly matte, string-free wall

How to print

• Nozzle temperature: 230–250 °C
• Bed temperature: 70–90 °C
• Cooling: 30–60% — too much hurts layer adhesion
• Speed: 40–80 mm/s, slower than PLA
• Adhesion: PETG sticks VERY hard — use glue stick as a release layer or it will chip the bed coating
• Retraction: a bit more than PLA to fight stringing

Drying and storage

PETG is hygroscopic — it absorbs moisture from the air. Wet PETG strings heavily, hisses, and loses strength.

• Drying: 60–65 °C for 6–8 hours
• Storage: airtight box with silica gel, especially in humid climates
• Signs of moisture: hissing/steam while printing, heavy stringing, cloudy surface

Pros and cons

• Tough and slightly flexible — survives impacts
• Water- and chemical-resistant, outdoor-capable
• Low warp, prints without an enclosure
• Available in transparent grades

• Loves to string — needs retraction tuning
• Sticks too well to the bed and to itself
• Sensitive to moisture
• Worse than PLA at small sharp details