PLA and PETG are two of the most popular 3D-printing materials for hobbyists. Both are easy to print on machines like the Ender 3 or Prusa Mini, but they behave very differently under load. PLA is strong and rigid, while PETG is tougher and more forgiving. (Note: PLA+ exists as a tougher version of PLA, but this article focuses only on standard PLA vs PETG.)
Tensile Strength: Stiffness vs Flexibility
PLA typically shows higher tensile strength on paper. Manufacturer data lists PLA around 60–72 MPa and PETG around 45–55 MPa. Real lab tests support this pattern: PLA dogbone tests show PLA reaching slightly higher maximum load before snapping.
However — and this is important — PLA is brittle. It snaps suddenly with almost no warning. PETG, on the other hand, stretches significantly before breaking. Many tests show PETG elongating several times more than PLA before failure.
Summary:
PLA = higher peak strength, very rigid, snaps suddenly.
PETG = slightly lower peak strength, tougher, bends instead of snapping.
Impact Resistance & Layer Adhesion
PETG wins easily when it comes to impact resistance. PLA behaves more like glass: strong but brittle. PETG absorbs shock much better. It also fuses layers more strongly, making PETG parts more resistant to layer-line breaks.
If you drop a PLA part, it may crack. If you drop a PETG part, it usually survives or deforms slightly.
Best choice for impact-loaded parts: PETG.
Temperature Resistance
PLA starts softening at around 55–60°C. That means:
- It cannot stay in a hot car
- It warps outdoors under sunlight
- It fails on warm appliances (e.g., near radiators)
PETG softens around 70–80°C, giving it noticeably higher thermal resistance. It is also more UV-resistant than PLA. PLA outdoors = very short lifespan.
PETG outdoors = safe for garden parts, car clips, brackets, etc.
Strength in Real-World Prints
Raw tensile strength is one thing — functional strength in real objects is another. Here is how PLA and PETG compare for everyday prints:
Brackets & Structural Parts
PETG is almost always the better choice. It bends under load and survives overstress events without snapping. PLA brackets are strong right until the moment they break.
Hooks, Clips & Hinges
PETG is superior. It flexes repeatedly without failing. PLA tends to crack along layer lines with repeated stress.
Tool Holders, Jigs & Workshop Parts
Both materials can work, but:
- PLA is better for precise, rigid jigs
- PETG is better for anything that experiences force or vibration
Outdoor Parts
PLA should not be used outdoors. PETG is a much better choice because it resists UV and heat.
Recommended Products (Amazon.de Ready)
These are not affiliate links yet — but the structure is ready for you to replace with your affiliate-tagged URLs.
- PLA Filament:
Search PLA Filament on Amazon.de - PETG Filament:
Search PETG Filament on Amazon.de - Digital Caliper (for measuring strength tests):
Search Digital Calipers - Hook Scale (for pull-tests):
Search Hanging Scales
Bottom Line
When to choose PLA:
✔ Beautiful surface quality
✔ Easy to print
✔ Great for prototypes, models, jigs
✘ Not impact-resistant
✘ Not heat-resistant
✘ Not outdoor-safe
When to choose PETG:
✔ Strong, flexible, impact-resistant
✔ Much better layer adhesion
✔ Better for functional parts and outdoors
✘ More stringing
✘ Slightly trickier to tune than PLA
In real-world functional prints, PETG often outperforms PLA despite PLA’s higher tensile strength on paper. For brackets, hooks, clamps, and outdoor use — PETG is the safer, stronger material.