PETG vs PLA: The Ultimate Strength Comparison Guide for 3D Printing

Sergio Peciña

Jul 9, 2025

PETG vs PLA filament comparison — 3D printed parts showing strength, flexibility and impact resistance differences | Eolas Prints

When choosing between PETG and PLA filaments for your next 3D printing project, understanding their mechanical properties can make the difference between a successful print and a failed one. At Eolas Prints, we manufacture both materials in-house in Cantabria, Spain, ensuring consistent quality backed by our ISO 9001 and ISO 14001 certifications.

Understanding the Strength Fundamentals

Tensile Strength: The Numbers Tell Part of the Story

PLA typically demonstrates higher raw tensile strength at around 50–60 MPa, while PETG ranges from 40–50 MPa. However, these numbers only tell part of the story. PLA's strength comes with a critical weakness — brittleness. When PLA reaches its limit, it fails catastrophically, shattering rather than deforming.

PETG, despite lower tensile numbers, exhibits superior toughness. It can absorb significantly more impact energy before failure, making it ideal for functional parts that need to withstand real-world stress.

Side-by-Side Comparison

Property	PLA	PETG
Tensile strength	50–60 MPa	40–50 MPa
Heat deflection temperature	~55–60°C	~62°C
Impact resistance	Low — brittle failure	High — absorbs impact
Moisture sensitivity	Low	High — dry before use
Shrinkage / warping	Minimal	Virtually zero
Print speed (standard)	40–100 mm/s	20–80 mm/s
Print speed (high speed printers)	Up to 300 mm/s	Up to 150–200 mm/s
Colour availability	20+ colours	Multiple colours
Food contact safe	Yes	Yes
UV resistance	Poor	Moderate (UV variant: excellent)
Chemical resistance	Low	High
Post-processing	Sand, paint, glue	Sand, paint, glue
Enclosure needed	No	No (helpful for large parts)
Relative cost	Lower	~15–20% higher

Temperature Performance: A Critical Factor

PLA begins softening around 55–60°C — meaning a car dashboard in summer can deform a PLA part. PETG maintains integrity up to approximately 62°C, which is meaningfully better for parts near heat sources, in kitchens, or in outdoor summer applications.

If you need heat resistance above 62°C, consider ASA (85°C HDT) or ABS (83°C HDT), or our PLA Ingeo 850 which reaches 85°C after annealing.

Impact Resistance: Where PETG Shines

The most significant difference in real-world use is impact behaviour. PLA fails suddenly — it shatters. PETG deforms and absorbs energy before failing. This makes PETG the right choice for protective cases and housings, tool handles and grips, mechanical components subject to vibration, and anything that might be dropped or knocked around.

PLA's rigidity makes it excellent for structural components that need to hold their shape precisely, but poor for anything requiring shock absorption.

Moisture and Storage

This is one of the most practically important differences and is rarely discussed. PLA is relatively moisture-resistant — you can leave an open spool for weeks without significant quality degradation in most climates. PETG is highly hygroscopic: it absorbs atmospheric moisture quickly, which causes stringing, popping sounds during printing, and surface bubbling. Dry PETG at 65–70°C for 4–6 hours before printing if it has been exposed to air for more than a few days. Store in sealed containers with desiccant.

Real-World Application Guide

Choose PLA when:

Learning 3D printing or teaching others — low warping, forgiving temperature range
Prototypes, models, and decorative items where impact resistance is not critical
Working in temperature-controlled indoor environments below 55°C
Printing speed matters — PLA can run at up to 300mm/s on High Speed PLA variant
Colour range matters — PLA has the widest selection including silk, matte, neon, and transition
Budget is a priority — PLA is 15–20% less expensive than PETG

Choose PETG when:

Creating functional parts that will be handled, dropped, or stressed in use
Parts will be exposed to temperatures above 50°C
Chemical resistance is needed — PETG resists oils, cleaning agents, and mild solvents
Outdoor use at moderate temperatures (or use PETG UV Resistant for certified outdoor durability)
Near-transparent or translucent parts are required
Food contact applications requiring durability and chemical resistance

Quick Decision Reference

Use case	Best choice
Beginner first prints	PLA
Decorative objects and models	PLA
High-speed printing (300mm/s)	PLA (High Speed variant)
Functional brackets and housings	PETG
Kitchen and food-contact items	PETG
Parts exposed to impact or vibration	PETG
Outdoor parts (UV certified)	PETG UV Resistant or ASA
Heat resistance above 62°C	ASA / ABS / PLA Ingeo (annealed)
Widest colour range	PLA
Maximum clarity / transparency	PETG

Expert Recommendation from Eolas Prints

Both materials are manufactured in-house at our Cantabria facility to ISO 9001 and ISO 14001 standards. Our recommendation: keep both in stock. PLA for design, prototyping, and education — PETG for anything functional that will see real use.

Shop the range: PETG Filament | PETG UV Resistant | PLA 1.75mm | High Speed PLA — ISO and REACH certified, made in Spain.