PCTG vs PETG: Which Should You Print With?

The short answer. If your parts get dropped, flexed, snapped together, left in the sun or wiped down with chemicals, print PCTG. It has 8-12x the impact toughness of PETG, resists more chemicals and UV, handles more heat, and prints at PETG-like settings. If you're printing storage bins, prototypes or indoor parts that never take a hit, a good PETG is fine and costs a little less.

We make both Pro PCTG and Pro PETG on the same lines in Fargo, North Dakota. Pro PETG is a high-grade PETG, not a budget one, so this is a comparison between two good materials, and we don't have a reason to oversell either. Here's how they compare.

PCTG vs PETG at a glance

Values are from our technical data sheets. Pro PCTG TDS · Pro PETG TDS

What those numbers mean in a printed part

Here is what each data-sheet number means once the material is a part on your bench.

• Notched Izod impact is the one that matters most. It measures how much energy a part absorbs when it's struck at a weak spot (the notch stands in for a sharp inside corner or a layer line). High Izod means a bracket survives being dropped, a clip survives being pried open and a housing survives a tool landing on it. This is where PCTG and PETG differ most: 93 vs 7.3 kJ/m² notched Izod, or 8-12x the impact toughness.
• Tensile strength at yield is the pull a part takes before it permanently stretches. Both materials are in the same range (44 vs 49 MPa), so for a part that's loaded slowly and steadily, a hook, a strap mount, a shelf bracket, PETG and PCTG hold about the same. The difference shows up when the load is sudden.
• Flexural modulus is stiffness. PETG is slightly stiffer (1,800 vs 1,600 MPa), which is why a thin PETG wall feels a little more rigid and a thin PCTG wall flexes a little more before it fails. If you need a part not to deflect at all, add a wall or a rib; if you need it to take a hit, the lower stiffness is part of why PCTG survives.
• Heat deflection temperature is where a loaded part starts to sag. The 0.455 MPa figure is the one to use for lightly loaded parts (76 °C PCTG, 72 °C PETG); the 1.82 MPa figure is for parts under real load (64 vs 62 °C). A printed part in a hot car or next to a motor needs a margin below these.
• Elongation at break, not in the table, is how far the material stretches before it tears: both are well over 100%, which is why neither snaps like PLA. Layer lines cut this down a lot, so print orientation matters more than the number.

Two rules that apply to both materials: a printed part is strongest along the layer direction and weakest across it, so orient the part so the load runs along the layers; and strength depends on how well the layers bonded, which for PCTG means printing hot enough and slow enough that the surface comes out glossy.

What PCTG actually is

PCTG and PETG are both glycol-modified copolyesters. PCTG swaps much of the ethylene glycol in PETG for cyclohexanedimethanol (CHDM). That one change is why PCTG soaks up an impact instead of cracking, resists more chemicals and absorbs less moisture, while still printing at temperatures close to PETG. For the full story, including the spec sheet, test data by print orientation and a complete settings table, read the PCTG filament guide. For the shorter version, read What Is PCTG Filament?

Toughness: the reason to switch

Strength and stiffness are about the same; PETG is a little stiffer. The difference is what happens when a part takes a hit. A PETG bracket dropped on concrete tends to crack or shatter. The same bracket in Pro PCTG flexes, and if it does fail, it bends and tears instead of breaking into sharp pieces.

That makes PCTG the better choice for clips and snap-fits, tool holders, drone and RC parts, protective housings, cosplay armor, and anything that lives in a garage, a truck or outdoors.

Heat

How much more heat PCTG takes depends on which PETG you compare it with. Against a typical budget PETG, Pro PCTG handles roughly 5-15 °C more. Against our own Pro PETG, a high-grade PETG near the top of the PETG range, the data-sheet gap is smaller: heat deflection of 76 °C vs 72 °C (ISO 75, 0.455 MPa). Neither unfilled material is a high-heat material. If your part needs more, stay in the family. The fiber-filled grades hold their shape under load at higher temperatures: heat deflection at 1.82 MPa is 64 °C for Pro PCTG, 73 °C for Pro PCTG-GF10 and 76 °C for Pro PCTG-CF10 (ASTM D648), and at 0.455 MPa it is 74, 78 and 79 °C. They are also much stiffer: flexural modulus 1.6x (GF10) and 3.5x (CF10) that of unfilled Pro PCTG. The trade is impact toughness: notched Izod is 860 J/m for unfilled Pro PCTG, 214 J/m for GF10 and 53 J/m for CF10 (ASTM D256), so pick GF10 or CF10 for stiff, hot, dimensionally stable parts and unfilled Pro PCTG for parts that get hit. All three print at the same 250-280 °C settings; the fiber grades need a hardened nozzle. Pro PCTG can't be annealed for more heat; it's amorphous and will distort.

Chemicals and UV

In our soak tests Pro PCTG held up to isopropyl alcohol and ethanol without cracking, kept its strength in gasoline and mineral spirits, didn't swell in engine oil or hydraulic fluid, and stayed stable in bleach and degreasers.

On UV, we tested both. In 2,000 hours of accelerated weathering, Pro PCTG held its color about twice as well as Pro PETG, and Pro PETG is already a high-grade PETG. That is why customers use Pro PCTG for outdoor mounts, garden parts, signage and anything that lives in the sun. For parts that must hold their color for years in full sun, ASA is still the right material.

Moisture and drying

PCTG absorbs moisture more slowly than PETG, but both print better dry. Dry Pro PCTG at 70 °C for 6-8 hours (or 65 °C for 8-12 hours) and Pro PETG at 65 °C for 8-12 hours. Store both sealed with desiccant. Full details: Drying and Storing Pro PCTG.

Printing: what's different

PCTG prints at PETG-like temperatures, but it's thicker when molten, so three things change:

1. Slow down a little. Keep outer walls and top surfaces at 100 mm/s or less (about 50 mm/s for the best finish) and acceleration at 2,000 mm/s² or less.
2. Calibrate pressure advance. Don't reuse your PETG value. This is the single biggest factor in clean PCTG prints. Here's how.
3. Turn the fan down. Use as little part cooling as you can, starting at 5% and topping out around 30-40%. A glossy surface means good layer bonding; a matte band means too fast, too cold or too much fan.

The easiest way to skip all of this is our tested profile for your printer: Pro PCTG Print Profiles. The full slicer-setting comparison is in the wiki: Printing Pro PCTG vs. PETG: What's Different.

When PETG is the better pick

• Fast, cheap, low-stakes parts. Storage containers, prototypes, jigs that won't take a hit and light outdoor use. PETG prints a bit faster with less tuning and costs a dollar less per spool.
• Maximum stiffness in a thin wall. PETG's flexural modulus is about 12% higher, so a thin PETG panel deflects a little less under the same load. Add a rib or a wall in PCTG and the difference disappears.
• A PETG workflow that already works. If your PETG parts aren't cracking, you don't need to switch.

Two things that are not a reason to pick one over the other: clarity, because both print exceptionally clear (90% light transmittance for each), and bed adhesion, because both bond hard enough to damage bare smooth PEI. With either material, use textured PEI or a glue-stick release layer on smooth sheets.

Which Pro PCTG should you start with?

• Everyday functional parts: Pro PCTG in Midnight Black, Brightest White or a Toolbox color. 60 colors and counting.
• A true matte finish: Pro PCTG Matte Black (hardened nozzle).
• Stiffer parts, or parts that see more heat: Pro PCTG-CF10 (carbon fiber) or Pro PCTG-GF10 (glass fiber). Both need a hardened nozzle.
• The lowest price per kg: ReFuel Recycled Pro PCTG, the same grade made from color-transition spools.

PCTG vs PETG FAQ

Is PCTG better than PETG? For parts that need toughness, chemical resistance or UV resistance, yes. Pro PCTG has 8-12x the impact toughness of PETG. For low-stakes parts or maximum clarity, a good PETG is fine.

Can I use my PETG settings for PCTG? Mostly for temperatures, not for speed. Print 250-280 °C, slow outer walls to 100 mm/s or less, lower the part fan and calibrate pressure advance. PETG settings carried over unchanged are the top cause of poor first PCTG prints.

Do I need an enclosure for PCTG? No. If your printer has one, keep it closed; it helps layer bonding.

Do I need a hardened nozzle? Not for standard colors, including transparent and translucent. Matte Black, CF10 and GF10 contain fibers and need a hardened nozzle.

Can I print Pro PCTG in a Bambu Lab AMS? Yes. Our 1 kg spool dimensions are compatible with the Bambu AMS, AMS 2 Pro and AMS HT, and our profiles are named "PCTG Pro" so the AMS recognizes the material.

Is PCTG more heat resistant than PETG? Yes: roughly 5-15 °C more than a typical PETG, and 4 °C more heat deflection than our own high-grade Pro PETG (76 vs 72 °C).

Is PCTG food safe? The resin is approved for food contact, but printed parts aren't automatically food-safe because layer lines trap bacteria. Use a food-safe coating.

What does PCTG stand for? Polycyclohexylenedimethylene terephthalate, glycol-modified.

Written by John Schneider, founder of 3D-Fuel. Updated October 2026.