Four materials cover 95% of the FDM jobs that come through our shop: PLA, PETG, ABS, and PET-CF (carbon fiber nylon). 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.
- PLA → prototypes, visual models, indoor parts under 50 °C
- PETG → outdoor parts, water contact, impact-prone parts
- ABS → heat-resistant housings, machinable parts, acetone smoothing
- PET-CF → structural brackets, drone frames, anything that needs stiffness
The comparison table
| Property | PLA | PETG | ABS | PET-CF |
|---|---|---|---|---|
| Tensile strength (MPa) | 50 | 50 | 40 | 80+ |
| Stiffness | Medium | Medium | Medium | High |
| Impact resistance | Low (brittle) | High | Medium | Medium |
| Max service temp | ~55 °C | ~75 °C | ~95 °C | ~110 °C |
| UV / outdoor | Poor | Good | Fair | Good |
| Print difficulty | Very easy | Easy | Hard (warps) | Medium |
| Food-safe* | Possible | Possible | No | No |
| Our price ($/cm³) | $0.035 | $0.045 | $0.055 | $0.125 |
*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.
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 (softens around 55 °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 above ~75 °C — step up to ABS or PET-CF
If you’re unsure between PLA and PETG for a functional part, choose PETG. The ~25% price bump ($0.045 vs $0.035 per cm³) buys you impact resistance and UV stability that saves the part from failing in the field.
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 nylon
PET-CF is our structural material. It’s PETG-based nylon 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 wears out hardened steel nozzles fast) and ~3.5× 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. The carbon fiber drone UAV industry page has real part examples.
How to pick: a 3-question flowchart
- Does it go outdoors, get wet, or take impacts? → PETG.
- Does it need to stay rigid under load, or weigh as little as possible while being stiff? → PET-CF.
- Will it get hotter than 55 °C, or need acetone smoothing/paint? → ABS.
- 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?
In the FDM materials we use, PET-CF is strongest by a wide margin (~80 MPa tensile vs 40–50 for PLA/PETG/ABS), especially in stiffness. For raw tensile it’s close to PLA and PETG — the real win is dimensional stability and creep resistance.
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?
A lot. PLA to PET-CF is a 3.5× price jump for the same volume. For a 30 cm³ part, that’s $1.05 vs $3.75. Usually negligible on small parts, meaningful on larger production runs. 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.