| Attribute | ABS Filament | PETG Filament | What This Tells You |
|---|---|---|---|
| Polymer Family | ABS (styrenic engineering thermoplastic) | PETG (glycol-modified polyester family) | Baseline chemistry influences heat feel, surface, and bonding behavior. |
| Density (g/cm³) | 1.05 | 1.27 | Helps estimate part weight and spool consumption for the same model volume. |
| Tensile Strength (MPa) | 45 | 49 | Both sit in a similar strength band; design and layer direction still matter a lot. |
| Tensile Modulus (GPa) | 2.03 | 2.15 | A quick read on stiffness under load; higher usually means less flex for the same geometry. |
| Elongation at Break (%) | 10 | 24 | Often reflects how a material “gives” before fracture; PETG commonly shows more ductile stretch. |
| Recommended Nozzle Temperature (°C) | 240 | 220–250 | Where consistent flow and layer fusion tend to land; actual ranges vary by brand and color. |
| Recommended Bed Temperature (°C) | 80–100 | 70–100 | Bed heat supports first-layer stability and overall flatness on larger footprints. |
| Suggested Fan Range | 0% | 0–30% | Cooling strategy shifts the balance between detail and interlayer bonding. |
| Heat-Related Indicator (as listed) | Vicat 105°C | Melting Point 180°C | These are different test concepts; treat them as context, not a one-to-one “winner” metric. |
| Optical / Visual Note (as listed) | — | 90% Transmittance | PETG often supports clear/transparent looks when the formulation and print settings align. |
Reading note: The numbers above are real datasheet values for specific ABS and PETG filaments. Across the market, additives, colorants, and brand recipes can shift these figures.
- Material Identity and Polymer Structure
- Thermal Behavior and Heat-Related Specs
- ABS Thermal Personality
- PETG Thermal Personality
- How To Read Vicat, HDT, and Tg Without Confusion
- Mechanical Behavior You Can Feel in Parts
- Dimensional Behavior and Printer Environment
- ABS Dimensional Personality
- PETG Dimensional Personality
- Surface, Detail, and Finishing Character
- Chemical and Moisture Response in Everyday Use
- What “Moisture Sensitivity” Usually Looks Like
- Spec-Sheet Phrases That Mean Real Things
- ABS heat-oriented feel
- PETG ductile feel
- Both: functional parts
- Both: wide availability
- Both: post-processing friendly
ABS and PETG are two workhorse materials in FDM 3D printing. Their spec sheets look similar at first glance, yet the way they behave in real prints can feel very different. This comparison focuses on measurable properties and repeatable traits, so you can read a spool label with more confidence.
Material Identity and Polymer Structure
- ABS Meaning
- Acrylonitrile Butadiene Styrene is a widely used engineering plastic known for a balanced mix of toughness, machinability, and a familiar “solid” feel in parts.
- PETG Meaning
- Polyethylene Terephthalate Glycol (PETG) is PET with glycol modification in the chain, which supports clarity, formability, and strong layer bonding in common 3D-print formulations. ✅Source
In plain terms, ABS often reads as a classic engineering plastic, while PETG behaves like a clear, tough polyester. Both can deliver dimensionally useful parts, and both respond strongly to print environment and formulation details.
Why structure matters: Polymer structure strongly influences heat response, surface feel, and how easily a part can flex under load. Those effects show up even when two spools share similar “strength” numbers.
Thermal Behavior and Heat-Related Specs
Thermal specs are where ABS and PETG start to separate in a meaningful way. The most useful concept is glass transition temperature (Tg): it marks the shift from a “glassy” feel to a more rubbery response as temperature rises.
ABS Thermal Personality
- Tg commonly reported around 100–105°C for ABS. ✅Source
- Higher Tg feel supports shape retention when a part lives near warm surfaces.
- ABS prints often appreciate a stable thermal zone for consistent geometry on larger footprints.
PETG Thermal Personality
- Tg for clear Eastman copolyesters used in packaging is listed at about 80–84°C, a useful reference point for PETG-type behavior. ✅Source
- PETG often keeps a tough feel while still offering ductility at room conditions.
- Warm environments can change stiffness earlier than ABS, depending on part design and load style.
How To Read Vicat, HDT, and Tg Without Confusion
- Tg is a material “feel shift” point; it’s closely tied to creep and how a part handles warm conditions.
- Vicat is a softening-style metric under a defined load; it’s useful for comparisons inside one material family.
- HDT (heat deflection) speaks to bending under load at temperature; it often aligns with functional load scenarios.
Mechanical Behavior You Can Feel in Parts
From many filament datasheets, ABS and PETG can look close on tensile strength and stiffness. The “feel difference” usually comes from ductility, surface energy, and how the material behaves at layer boundaries. Think structure plus print history, not just one headline number.
Relative Ductility Feel (based on common datasheet patterns)
Relative Stiffness Feel (typical mid-range comparison)
Layer-Bond Confidence (how many users describe it)
A useful mental model: ABS often reads as crisp and stable under warmth, while PETG often reads as tough and forgiving under impact-style handling. Neither is “better” in a vacuum; they simply express different mechanics.
Dimensional Behavior and Printer Environment
ABS and PETG both reward a stable print environment, yet in different ways. ABS tends to prefer even heat across the build area. PETG tends to reward consistent extrusion and controlled cooling so surfaces stay clean and edges stay sharp.
ABS Dimensional Personality
- Often associated with stable geometry once the thermal zone is even.
- Commonly printed with lower fan to support layer fusion.
- Large flat parts often benefit from a steady temperature field across the plate.
PETG Dimensional Personality
- Often chosen when layer bonding and toughness are a priority.
- Can keep corners tidy with moderate cooling while still maintaining strong fusion.
- Transparent looks often pair well with smooth flow and consistent line width.
Surface, Detail, and Finishing Character
Surface results are shaped by flow, cooling, and the polymer’s natural shine. ABS often presents a classic solid-plastic finish that takes sanding and paint well. PETG is known for clear or glossy aesthetics and a “tough-smooth” surface feel.
- ABS: surfaces often feel firm; detail can look crisp when cooling and flow are balanced.
- PETG: surfaces often look glossy; the material can show transparent effects when the formulation is clear.
- Both: post-processing tends to respond well to light sanding and careful finishing for display-grade parts.
Chemical and Moisture Response in Everyday Use
In day-to-day handling, both ABS and PETG are commonly described as durable plastics. For printing consistency, moisture sensitivity matters: many users treat filament as a dry-material system because stable extrusion supports better surfaces and repeatable strength.
What “Moisture Sensitivity” Usually Looks Like
- More moisture often means less consistent flow and more surface variation across layers.
- Dryer filament typically supports steady extrusion, which supports tight tolerances and cleaner walls.
- This is a general polymer behavior; the exact sensitivity depends on the brand formulation and storage conditions.
Spec-Sheet Phrases That Mean Real Things
When you compare ABS and PETG, spec sheets usually repeat a handful of phrases. Reading them with the right lens keeps the comparison clean and useful, without guessing.
- “Tensile Strength”
- A lab pull test number that describes how a standardized bar behaves in tension. It’s a strong indicator for material family, while real parts still depend on layer orientation.
- “Elongation at Break”
- A quick view of stretch before break. Higher values often align with a more ductile response in everyday handling.
- “Nozzle / Bed Temperature”
- Not a single magic number; it’s a process window. It helps you compare how hot each polymer likes to flow and adhere.
- “Transmittance / Clarity”
- A clue for transparent aesthetics. PETG-type materials can support clear looks, especially when the formulation and print lines cooperate.
