PLA vs PETG: Which Filament Should You Choose?

Strength and Rigidity

On paper, PLA and PETG are surprisingly close in tensile strength. Across 275 PLA filaments with valid data, tensile strength ranges from 10.8 to 75 MPa with a median of 45 MPa. PETG (108 filaments) runs 22–80.6 MPa with a median of 48 MPa — a modest 7% advantage. In practice, that gap rarely determines a part's success.

Where they diverge is stiffness. PLA's flexural modulus (a measure of resistance to bending) has a median of 2,700 MPa across 214 filaments with data — about 30% higher than PETG's median of 2,040 MPa across 76 filaments. That stiffness makes eSUN PLA-Basic (63.95 MPa tensile, 101.2 MPa flexural) feel rigid and predictable for brackets and structural parts. But rigidity is a double-edged sword: PLA is more brittle. Its elongation at break (how much it stretches before snapping) ranges from 0.5–44% with a median of 8% across 261 materials. PETG stretches more — 1.8–98% range, median 9.3% across 110 materials — which means it bends slightly before breaking rather than cracking suddenly.

Impact resistance tells a nuanced story. PLA's median impact strength is 12.8 J/m across 221 filtered materials; PETG comes in at 8.6 J/m across 74 filtered materials. But the ranges are wide and product-dependent — Elegoo PETG Translucent hits 76.4 J/m, while standard PLA variants cluster around 10–20 J/m. If impact resistance is critical, look at specific TDS values rather than family averages.

Heat Resistance: Where PETG Wins Decisively

This is the most important difference for functional parts. PLA's heat deflection temperature (HDT) ranges from 45–115°C across 226 materials, but the median is just 55°C — warm enough to deform in a car interior on a sunny day (dashboards can reach 70–80°C). Its Vicat softening point median is 61°C across 142 materials. Standard PLA will warp, sag, or lose dimensional accuracy in environments above ~55–60°C.

PETG is meaningfully better. Its HDT ranges 58–96°C with a median of 70°C (90 materials). The Vicat softening point tells the same story: median 82°C across 63 PETG materials, vs PLA's 61°C. Prusament PETG (47 MPa tensile, 68°C HDT) and Elegoo PETG Pro (40 MPa tensile, 73°C HDT) are representative of typical PETG performance. That extra 15°C of thermal headroom matters for enclosures near electronics, light fixtures, or anything left in a vehicle.

Glass transition temperature (Tg) confirms the pattern. Across 15 PLA materials with Tg data, the average is 56°C. The two PETG materials with Tg data average 74.8°C. Once a material exceeds its Tg, it softens rapidly — PLA's functional temperature ceiling in practice is around 55–60°C, PETG's is closer to 70–75°C.

Printability: PLA's Home Turf

PLA prints at 190–220°C nozzle temperature in typical conditions — across 496 materials with data, the median minimum is 190°C and the overall range is 140–250°C. PETG needs more heat: median minimum of 230°C, with a range of 195–300°C across 170 materials. Higher temperatures mean more potential for stringing and oozing with PETG, and most PETG materials benefit from a retraction and temperature tuning session.

Bed temperatures reflect the same gap. PLA's median bed temperature is 40°C minimum, 60°C maximum — and 84 out of 461 PLA materials specify a minimum bed temp of 25°C or less, meaning they can print on a cold or lightly warm bed. PETG almost always wants a heated bed: 85 of 159 PETG materials specify a minimum bed temp of 70°C or above, and the median is 70°C. If your printer lacks a heated bed, PLA is the practical choice.

PETG also has a reputation for adhesion aggression — it can bond so strongly to glass or PEI surfaces that it lifts the surface when removed. Most users apply a release agent (glue stick, hairspray) or use a textured PEI sheet. PLA is more forgiving on bed adhesion in both directions: it sticks well enough and releases cleanly.

On the other hand, PETG doesn't warp. PLA can warp on larger prints without a good first layer and bed adhesion, but PETG's low shrinkage and moderate bed temperature make it extremely warp-resistant — it outperforms ABS significantly on that dimension, and matches or beats PLA on larger flat parts.

Moisture and Chemical Resistance

PLA is hygroscopic and degrades over time with moisture exposure — it's biodegradable by design, which means outdoor parts made from PLA will visibly degrade within months to a few years depending on UV exposure and humidity. PETG is chemically a PET derivative (the same plastic in drink bottles), which gives it significantly better moisture resistance. For parts that will see rain, humidity, or outdoor conditions, PETG is the clear winner.

PETG is also more chemically resistant to mild acids, bases, and some solvents than PLA. Neither is suitable for strong solvents or fuels, but PETG handles a wider range of real-world chemicals. If you're printing a container for liquids, a bathroom fixture, or anything in a garage or kitchen environment, PETG is the safer choice.

Density and Cost

Both materials are similar in density: PLA median 1.24 g/cm³, PETG median 1.27 g/cm³, across 317 and 117 materials respectively. You'll get very similar part weights from the same volume of material.

No price data is currently tracked in the Filabase database, but PLA is generally 10–25% cheaper than PETG at retail (based on typical market pricing as of early 2026). PLA is the default filament for most desktop printers and benefits from enormous competition and production volume. PETG has caught up significantly and is widely available from the same brands — Polymaker PolyLite PETG (50.8 MPa tensile, 78°C HDT, 84°C Vicat) and Jayo PETG (61.4 MPa tensile, 63°C HDT) represent the accessible end of the PETG market.

Side-by-Side Comparison

Here are the key differences at a glance — based on median values across our database:

When to Use PLA

• Prototypes and models — stiff, dimensionally accurate, easy to dial in
• Indoor decorative parts — figurines, display models, cosplay props
• Parts that won't see heat above 55°C — office accessories, holders, mounts away from heat sources
• Beginners — lowest print temperature, widest printer compatibility, most forgiving first layer
• High-detail prints — PLA's lower stringing tendency and sharper bridging make it easier for detailed models
• Budget-conscious projects — PLA is typically the most affordable option per kilogram

When to Use PETG

• Functional mechanical parts — brackets, clips, jigs, tooling that needs to flex slightly without snapping
• Outdoor or semi-outdoor applications — PETG's moisture and UV resistance significantly outlasts PLA
• Parts near heat sources — cable management near PSUs, light fixture mounts, motor mounts (up to ~65–70°C)
• Food-adjacent parts — PETG is more chemically inert than PLA (though layer adhesion means no printed part is truly food-safe without post-processing)
• Parts that need to survive washing — PETG won't deform in hot water up to its HDT; PLA may soften in a dishwasher
• Enclosures for electronics — better thermal headroom and moisture resistance than PLA

What the Database Tells Us

Filabase tracks 533 PLA filaments from dozens of brands — the largest single polymer family in our database — reflecting PLA's position as the default desktop printing material. Our 185 PETG filaments span standard grades, high-speed variants like Eryone Hyper Speed PETG (50.1 MPa tensile, 69°C HDT), and specialty grades with carbon or glass fiber reinforcement.

One pattern visible across the database: PETG product lines tend to show more consistency in published specs. Of 110 PETG materials with tensile strength data, the range is 22–80.6 MPa with the majority clustering between 40–55 MPa. PLA shows more variance (10.8–75 MPa across 275 materials), partly because it covers a wider range of specialty blends — silk, matte, wood-filled, and foam — that alter mechanical properties significantly.