3D printingPLA and PETG are the two most common filaments in desktop 3D printing, and for most projects one of them is the right answer. They look similar on the spool but behave very differently once they're printed. Here's a plain comparison of the two, when to use which, and a real example from our studio where we use both in the same object.
Quick answer
The short version
- PLA is the easiest filament to print. It's stiff, holds crisp detail and comes in the widest range of colors and finishes. It softens at fairly low temperatures and can get brittle.
- PETG is tougher, more flexible, more heat tolerant and better outdoors. It can be clear or translucent. It's a little fussier to print, with more stringing.
If your part lives indoors, doesn't get hot and needs to look sharp, use PLA. If it needs to survive heat, impact, sunlight or moisture, use PETG.
01
What they are
PLA (polylactic acid) is a bioplastic usually made from plant starches such as corn or sugarcane. It's often described as biodegradable, but in practice it only breaks down in industrial composting conditions, not in a landfill or backyard compost.
PETG (polyethylene terephthalate glycol-modified) is a modified version of PET, the plastic used in water bottles. The added glycol makes it less brittle and easier to print.
02
PETG vs PLA comparison table
| Property | PLA | PETG |
|---|---|---|
| Ease of printing | Easiest. Low warping, forgiving settings | Moderate. Stringing, needs tuning |
| Typical nozzle temp | About 190–220 °C | About 220–250 °C |
| Typical bed temp | About 50–60 °C (or unheated) | About 70–85 °C |
| Heat resistance (glass transition) | About 55–60 °C | About 80 °C |
| Stiffness | High. Very rigid | Moderate. Slight flex |
| Impact resistance / toughness | Low. Snaps under shock | High. Bends before it breaks |
| Layer adhesion | Good | Excellent |
| Detail and surface finish | Crisp edges, matte to silky options | Glossier, slightly softer detail |
| Transparency | Mostly opaque; translucent grades are cloudier | Clear and translucent grades available |
| UV and outdoor use | Poor. Fades and becomes brittle over time | Better. Holds up reasonably outdoors |
| Moisture sensitivity | Moderate | Higher. Benefits from drying before printing |
| Chemical resistance | Low | Good |
| Food contact | Raw resin can be food-safe; printed parts usually aren't (see below) | Same caveats |
| Cost | Lowest | Usually similar or slightly higher |
Temperatures vary by brand, so always start with the manufacturer's recommended range.
03
Strength: it depends what you mean
People often say PETG is stronger than PLA. That's partly true.
- PLA is stiffer and often has a higher tensile strength. Pull on it slowly and it holds. Hit it or bend it and it snaps.
- PETG is tougher. It flexes and absorbs impact, so it survives drops and repeated stress that would crack PLA. Its layers also bond very well, which matters for parts loaded across the layer lines.
For brackets, clips, hinges and anything that gets knocked around, PETG usually lasts longer. For rigid parts that need to hold an exact shape, PLA is often better.
04
Heat resistance
This is one of the biggest practical differences. PLA starts to soften around 55 to 60 °C. That's lower than many people expect: a PLA part left on a car dashboard in summer can warp. PETG holds its shape until around 80 °C, giving it a much wider margin for anything that sits near warmth, like electronics enclosures, light fittings, or items near a sunny window.
Neither is suitable for genuinely hot applications like engine bays or kitchen utensils that touch hot food.
05
Ease of printing
PLA is the default for a reason. It prints at low temperatures, barely warps, bridges and overhangs cleanly, and is forgiving of imperfect settings.
PETG takes a little more care:
- Stringing. PETG tends to leave fine strands between features. Tuning retraction and temperature helps.
- Bed adhesion. PETG can stick too well to some smooth build surfaces, especially PEI, and pull chunks out. A release layer like glue stick is common.
- First layer. It prefers a slightly higher nozzle gap than PLA rather than being squished hard into the bed.
- Moisture. Wet PETG prints with bubbles and poor surface finish, so drying the spool helps.
06
Finish and appearance
PLA comes in the widest range of colors and specialty finishes: matte, silk, metallic, wood-filled and more. It produces sharp edges and fine detail, which makes it the favorite for models, figures and decorative objects.
PETG has a naturally glossier surface and is available in clear and translucent grades that let light through evenly. Fine detail is slightly softer, but for glowing or see-through parts, PETG is hard to beat among easy-to-print filaments.
07
Food safety caveats
You'll see both described as food safe. Be careful with that.
- The base resins of PLA and PETG can be food-contact approved, but colorants and additives in a given filament may not be.
- Printed parts have layer lines and tiny gaps where bacteria can grow, and they can't be sterilized at high heat without deforming.
- Brass nozzles can contain small amounts of lead.
For anything that touches food repeatedly, use filament certified for food contact by its manufacturer, a stainless steel nozzle and, ideally, a food-safe coating, or choose a different manufacturing method altogether.
08
UV and outdoor use
PLA is a poor choice outdoors. Sunlight and heat make it fade, soften and eventually crack. PETG handles sun and weather noticeably better and doesn't absorb much water once printed, so it's the better of the two for garden parts, outdoor mounts and items near windows. For long-term heavy sun exposure, filaments like ASA are better still.
09
When to use PLA
- Prototypes and test fits
- Display models, sculptures and figurines
- Decorative objects that need crisp detail
- Rigid indoor parts that won't get warm
- Prints where you want a specific color or specialty finish
10
When to use PETG
- Functional parts that take impact or flex
- Parts near heat sources, like lighting or electronics
- Outdoor or sunlit items
- Clear or translucent parts
- Containers and enclosures that need to be durable
11
A real example: why our lamps use both
Our IMPRESO x KUMO 3D printed lamps use a PLA base and a translucent PETG shade. Each material is doing what it's best at.
The shade is PETG because:
- It's translucent. PETG lets light through evenly, so the shade glows softly instead of showing a hot spot.
- It's close to the bulb. The lamps use LED bulbs, which run much cooler than incandescents, but the shade still sits nearest the light source. PETG's higher heat tolerance gives a comfortable safety margin over PLA.
- It's tough. A lamp shade gets bumped, moved and cleaned. PETG flexes instead of cracking.
The base is PLA because:
- Crisp detail. PLA holds sharp edges and fine surface detail, so the base reads as a clean, finished object.
- Stiffness. A rigid base keeps the lamp stable and the structure true.
- Distance from the bulb. The base doesn't get warm, so PLA's lower heat resistance isn't a concern.
That combination is a good rule for any multi-part project: put each material where its strengths matter and its weaknesses don't.
12
Custom 3D printing
Alongside our fine art printing, we take on custom 3D printing projects in Ridgewood, Queens. If you have a design you'd like printed, or an idea you want to develop, get in touch through our contact page with what you're making, rough dimensions and how it will be used, and we'll suggest the right material.
Let’s make it.
Send a file, a sketch or an idea, and we’ll suggest the right material and quote it. Printed in-house in Ridgewood, Queens. info@impreso.nyc · (201) 389-8639
Start a 3D project → See 3D printing →More guides
