PLA vs PETG vs ABS vs PET-CF: Which 3D Printing Material?

Four materials cover 95% of the FDM jobs that come through our shop: PLA, PETG, ABS, and PET-CF (carbon-fiber-reinforced PET). Each one has a clear sweet spot, and picking the wrong one is the #1 reason 3D printed parts fail in service. Here’s how we actually choose on a per-job basis.

The comparison table

*FDM parts are not inherently food-safe regardless of material — layer gaps harbor bacteria. Food-safe requires a coating and/or special print process. Ask us.

Tensile figures are filament-datasheet values measured by the ASTM D638 dumbbell tensile test (ASTM D638); heat deflection temperature is the ASTM D648 method, which ramps temperature under a constant flexural load until the specimen deflects a set amount (ASTM D648). Both are measured on moulded specimens, so treat them as a ranking between materials rather than a prediction of what your printed part will survive — a printed part is weaker than the datasheet, and by how much depends on orientation (see below).

PLA — the default for 90% of first prints

PLA (polylactic acid) is the easiest FDM plastic to print and the cheapest one we stock. It’s made from corn starch, prints at a relatively low 210 °C, and produces almost no smell. First-time 3D printing customers should start here unless they have a specific reason not to.

When to use PLA

• Visual prototypes — dimensional accuracy is excellent
• Cosmetic parts that live indoors
• Jigs, fixtures, and alignment tools (not load-bearing)
• Tabletop miniatures and display pieces
• Any “form & fit” check where strength doesn’t matter

When NOT to use PLA

• Anything left in a hot car (heat deflection temp is 52 °C)
• Outdoor parts exposed to UV — gets brittle in weeks
• Parts that take sudden impact — it snaps instead of bending
• Parts that hold continuous load — creeps (slowly deforms) under tension

PLA is also the cheapest on our materials page — $0.035/cm³. A coffee-mug-sized prototype runs under $10.

PETG — the unsung hero

PETG (polyethylene terephthalate glycol) is what most people should be printing instead of PLA when the part matters. It’s tougher, more impact-resistant, waterproof, and holds up outdoors. It’s the same family as water bottles — which is why it’s our go-to for anything touching water or weather.

When to use PETG

• Outdoor parts (garden, rooftop, marine)
• Watertight enclosures (it layer-bonds well)
• Parts that will take impacts or drops
• Chemical-resistant housings (handles most solvents)
• Low-stress mechanical parts that see sun or moisture

When NOT to use PETG

• Stringy / precision parts — PETG is slightly oozy by nature
• Parts needing sharp, crisp edges for display use — PLA wins
• Very hot environments — PETG’s heat deflection temp is 70 °C; step up to ABS or PET-CF above that

ABS — the classic engineering plastic

ABS (acrylonitrile butadiene styrene) is what LEGO bricks are made of. It handles heat, takes taps and threads well, can be sanded, glued with acetone, and vapor- smoothed to an injection-mold-like finish. It’s also the hardest of the four to print reliably — it warps badly on open beds. We print ABS in an enclosed chamber to get repeatable results.

When to use ABS

• Enclosures that live near heat (electronics, automotive bays)
• Parts that need tapped threads without heat-set inserts
• Parts you plan to sand, paint, or acetone-smooth
• Replacement parts for molded ABS products (matches material)

When NOT to use ABS

• UV-exposed parts — yellows and degrades in sunlight
• Food contact — contains styrene
• Large flat parts without chamber — warping is real

PET-CF — carbon-fiber reinforced PET

PET-CF is our structural material. It’s PET with short chopped carbon fibers mixed in (~15–20%). The fibers make it dramatically stiffer and dimensionally more stable than any of the above — at the cost of being abrasive (it shreds brass nozzles, so we run hardened steel) and ~2× the price of PLA.

When to use PET-CF

• Structural brackets that need to stay rigid under load
• Drone frames and UAV mounts — stiffness-to-weight is phenomenal
• Robotics end-effectors and arms
• Tooling — fixtures, jigs, soft jaws for CNC
• Parts that would otherwise need aluminum but at 1/5 the cost

When NOT to use PET-CF

• Visible cosmetic parts — finish is matte and fibers show on sanding
• Very small parts where PLA would be plenty — expensive overkill
• Parts needing maximum impact resistance — CF is stiff but brittle when flexed far

We keep PET-CF in stock in the materials catalog, and our carbon fiber 3D printing service covers how we run it — hardened nozzles, dried spools, real strength numbers. The carbon fiber drone UAV industry page has real part examples.

Where PLA-CF fits in — the fifth option

There’s a fifth material worth knowing if you like the idea of carbon fiber but don’t need PET-CF’s heat tolerance: PLA-CF, carbon-fiber reinforced PLA. It prints as easily as regular PLA — no enclosed chamber, no fuss — but the chopped carbon makes it dramatically stiffer and gives it a premium matte-black finish that hides layer lines. At $0.070/cm³ (2× PLA) it’s our mid-tier stiffness pick.

When to use PLA-CF

• Stiff parts that stay cool and indoors — camera rigs, brackets, lightweight jigs
• Anything where the matte carbon look matters — display models, RC body panels, props
• Large flat parts that warp in regular PLA — the carbon keeps them dimensionally stable
• A stiffer, better-looking upgrade from PLA when you don’t need PET-CF’s heat rating

When NOT to use PLA-CF

• Anything hot — it softens at 55 °C, barely above plain PLA’s 52 °C (the carbon does not meaningfully raise heat resistance)
• Parts that take impact or need to flex — it’s stiff but brittle
• Structural, load-bearing, or outdoor parts — step up to PET-CF or ABS

The short version: PLA-CF is for stiffness and looks; PET-CF is for stiffness under heat and load. PLA-CF prints far more easily, but it has no real heat resistance — it softens at 55 °C, essentially the same as plain PLA. If your part lives indoors at room temperature and you want it rigid and good-looking, PLA-CF is the easy choice; if it sees heat, load, or weather, step up to PET-CF. See it in the materials catalog.

How to pick: a 3-question flowchart

1. Does it go outdoors, get wet, or take impacts? → PETG.
2. Does it need to stay rigid under load, or weigh as little as possible while being stiff? → PET-CF.
3. Will it get hotter than PETG’s 70 °C, or need acetone smoothing/paint? → ABS.
4. None of the above? → PLA. You’ll save money and it’ll be fine.

Real-world examples from our shop

Drone arm (PET-CF)

A local UAV startup brought us a quadcopter arm they’d been printing in PLA. Every crash cracked the arm. Switching to PET-CF with the same geometry cut replacement rate by ~80% and added only 6 grams per arm.

Marine pool-timer housing (PETG)

A Carlsbad customer needed a weatherproof enclosure for an irrigation controller near a pool. We printed in PETG with 100% infill walls and gasket grooves. Two years in, still holding.

Display trophies (PLA)

Indoor, cosmetic, will never see heat or load. PLA is usually the right call — cheaper, sharper edges, better color range.

Heat-gun nozzle (ABS)

A customer needed a replacement handle grip that sits near hot air (~80 °C). PLA would deform; PETG was borderline. ABS gave them a long-service-life part.

Can you print PLA vs PETG vs ABS on the same printer?

Yes — modern FDM printers handle all three with profile changes. PET-CF needs a hardened nozzle (the fibers shred brass nozzles in hours). Our shop runs a mix of hardened-nozzle carbon-ready machines and enclosed chambers for ABS reliability.

Material FAQ

Which 3D printing material is strongest?

It depends which kind of strong you mean, and the honest answer is less dramatic than the marketing. Of the four here, PET-CF has the highest tensile figure at 65 MPa against 50 for PETG, 40 for ABS and 37 for PLA — a real lead, but not an order of magnitude. Its bigger advantage is stiffness and dimensional stability: it resists creep and holds its shape under sustained load where PLA slowly deforms. If you want the strongest thing we print, that is PA6-CF at 130 MPa with a 180 °C heat deflection temperature, not PET-CF.

One caveat that applies to every number on this page: those are datasheet values for moulded specimens. A printed part is weaker, because layers are a bonded interface rather than continuous material. Measured against injection-moulded ABS, FDM parts reached 65–72% of tensile strength and 80–90% of compressive strength, varying with raster orientation (Ahn et al., 2002). Orientation is a design decision, not a detail — a part loaded across its layers is the strong case, and one loaded to pull layers apart is the weak one.

PLA-CF or PET-CF — which carbon fiber should I pick?

Both are stiff and carbon-filled with the same matte look. Pick PLA-CF for rigid, good-looking parts that stay cool and indoors — it prints far more easily. Pick PET-CF when the part sees heat, sustained load, or the outdoors; PLA-CF softens at 55 °C, essentially the same as plain PLA. Same carbon look, very different temperature and toughness envelopes.

Is PLA or PETG easier to print?

PLA. PETG prints almost as reliably but has a tendency to ooze and string if not tuned. Both are reasonable on any modern printer.

Does PETG replace ABS?

For most hobbyist and prototype uses, yes — PETG is easier to print, less smelly, and tougher against impacts. ABS still wins on heat tolerance and acetone smoothing.

What’s the best material for outdoor 3D prints?

PETG is our default. UV-stabilized ASA is an even better outdoor choice if your part is exposed to direct sun for years — ask us about ASA if that’s you.

How much does material choice affect price?

Less than the raw material rates suggest. PET-CF costs 2× PLA per cm³, but a quote also prices machine time, so the finished part is about 1.6×: a 30 cm³ part quotes around $4.87 in PLA and $7.79 in PET-CF. Negligible on a one-off that lands on the $20 order minimum; meaningful across a production run. See our pricing breakdown for the full math.

Still unsure? Upload the file.

Our instant quote tool shows the price in every material we stock so you can compare side by side. If you’re picking between two, order one of each for a direct comparison — a 20 cm³ sample part in both PLA and PETG is under $45 total.