PLA vs. PETG: Weight, Strength, and Practicality
Choosing the right material for your project's specific needs.
PLA and PETG are the two titans of the consumer 3D printing world. Most makers start with PLA but eventually wonder if they should move to PETG for 'better' results. While they look similar on the spool, they are chemically distinct and require different approaches to design and printing. Understanding the trade-offs in weight, temperature resistance, and ease of use is key to project success.
Ease of Use: The PLA Advantage
PLA is widely loved because it is 'easy mode.' It prints at low temperatures (190-210°C), has almost zero warp, and doesn't require an enclosure. It's the best choice for decorative items, prototypes, and parts where dimensional accuracy is more important than heat resistance. However, PLA is brittle and will deform inside a hot car on a summer day.
Durability and Heat: Where PETG Shines
PETG is the 'grown-up' version of PLA. It is much more flexible (it bends instead of snapping) and can withstand temperatures up to ~80°C. This makes it suitable for outdoor use, mechanical brackets, and automotive accessories. PETG is also more chemically resistant than PLA, though it is more prone to 'stringing' and requires a hotter bed (70-80°C) and nozzle (230-250°C).
Weight and Density Differences
As our density calculators show, PETG (~1.27 g/cm³) is slightly denser than PLA (~1.24 g/cm³). For a standard 1kg spool, this translates to a few meters less filament. For most users, this difference is negligible, but for weight-sensitive applications like RC planes or drones, the lighter PLA (or the even lighter ABS) might be a better choice.
Layer Adhesion and 'Waterproofing'
PETG has superior layer-to-layer bonding compared to PLA. When printed correctly, PETG parts are often effectively 'watertight' and much harder to split along the layer lines. This makes it the preferred material for planters, food-safe containers (if the specific brand is certified), and any part that will be under constant mechanical stress.
FAQ
Is PETG stronger than PLA?
It depends on the definition of strength. PLA is harder and stiffer, but brittle. PETG is tougher and can survive impacts or bending that would shatter PLA. For most 'functional' parts, PETG is considered the stronger choice.
Which is more environmentally friendly?
PLA is derived from renewable resources like corn starch and is 'biodegradable' in industrial composting facilities. PETG is a petroleum-based plastic but is highly recyclable (Type 1 plastic), though 3D prints are rarely accepted by curbside recycling.
Do I need a different bed surface for PETG?
Yes. PETG sticks *too* well to glass and PEI. It can actually take chunks out of a glass bed if you aren't careful. Use a glue stick or hairspray as a 'release agent' when printing PETG on glass or smooth PEI.