Voron PETG Printing Guide — Strong Parts Without An Enclosure

Materials Printing Guide

PETG (Polyethylene Terephthalate Glycol) is one of the most versatile materials for Voron printers. It combines the ease-of-printing of PLA with significantly better strength, temperature resistance (glass transition ~80°C), and impact resistance. Unlike ABS, PETG does not require a heated enclosure — you can print it on an open-frame Voron Switchwire or even a V2.4 with the doors open. Last updated: May 2025.

This guide covers temperature tuning, bed adhesion (which is tricky with PETG), stringing and oozing fixes, layer adhesion optimization, PETG vs ABS for Voron parts, and the best PETG brands. Whether you're printing Voron mod parts, functional components, or prototypes, these settings will get you reliable results on any Voron model.

PETG vs ABS — When to Use Each on a Voron

Many Voron owners assume ABS is always the right choice. Here is when PETG is actually better:

• Non-structural mods and brackets: For parts that don't bear significant mechanical load and won't see high chamber temperatures (above 70°C), PETG is easier to print and cheaper.
• Prototyping and test fits: PETG prints faster than ABS (higher volumetric flow rates), requires no chamber preheating, and has lower warp tendency. Iterate in PETG, then print the final version in ABS if needed.
• Parts near electronics: Since PETG does not require a hot enclosure, you can print electronics enclosures, Raspberry Pi mounts, and fan shrouds without worrying about heat-soaking your electronics bay.
• Visual parts: PETG produces glossy, clear (or translucent) parts with excellent layer-to-layer transparency. Great for LED diffusers, window panels, and aesthetic mods.
• When NOT to use PETG: Do not use PETG for Voron structural printed parts (gantry mounts, AB drive units, extruder bodies, motor mounts). These parts sit inside the heated chamber and must withstand 60-70°C continuous temperatures. PETG softens at ~80°C and will creep under load. ABS or ASA are mandatory for Voron structural parts. Also avoid PETG for parts that contact the hotend or heater block — use ABS, PC, or nylon for those.

Print Temperature Settings

Bed Adhesion — The PETG Challenge

PETG has a reputation for sticking too well — or not well enough. The material bonds aggressively to some surfaces (smooth PEI, bare glass) to the point of tearing chunks out of the build plate. On other surfaces, it refuses to stick at all. Here is how to get it right:

• Textured PEI (Recommended): This is the best surface for PETG on a Voron. The textured surface provides excellent mechanical grip during printing, and PETG releases cleanly once the bed cools below 40°C. Clean with isopropyl alcohol between prints. Do NOT use acetone on PEI — it damages the surface. Bed temp: 70°C.
• Smooth PEI — Use with Caution: PETG can fuse permanently to smooth PEI. If you must use smooth PEI, apply a release agent (glue stick or Magigoo) as a barrier layer. Even with a release agent, let the bed cool completely before attempting part removal. Bed temp: 75°C.
• Glass with Hairspray: Clean glass with isopropyl alcohol, then apply a thin layer of Aqua Net or Aussie Freeze hairspray. The hairspray acts as both an adhesive and a release layer. PETG releases from glass naturally once cool. Bed temp: 75-80°C.
• Glue Stick (Magigoo or Pritt): Apply a thin layer to smooth PEI or glass. This creates a barrier that prevents PETG from fusing to the surface while providing adequate grip. Reapply every 3-5 prints. The most reliable method for difficult PETG adhesion cases.
• Blue Painter's Tape: An old-school method that works well for PETG. Apply 50mm wide tape to the bed, ensuring strips overlap slightly. PETG adheres well to the tape surface and releases cleanly. Con: leaves a textured bottom surface and the tape needs replacement after 5-10 prints.

Critical PETG adhesion tip: Unlike ABS (which benefits from being squished into the bed), PETG should NOT be over-squished. A first layer height of 0.2-0.25mm (not 0.15mm) with a 0.4mm nozzle gives the best results. The first layer should look slightly rounded on top — if it's transparent or razor-thin, your Z offset is too low. Too much squish causes PETG to curl up between the nozzle and the bed, creating blobs that can catch the nozzle on subsequent passes.

Stringing and Oozing — Taming PETG

PETG has a tendency to string and ooze more than PLA due to its higher melt viscosity and slower cooling rate. Here are the most effective fixes:

• Retraction tuning: Start with 0.8mm retraction at 35 mm/s. If you see stringing, increase retraction in 0.2mm increments up to 1.4mm. If you see blobs at the start of perimeters (from retraction delays), reduce retraction. On Voron direct-drive extruders (Clockwork 1/2, Galileo 2, Orbiter), 0.6-1.0mm is the sweet spot.
• Temperature reduction: PETG becomes more fluid and stringy above 240°C. Run a temperature tower from 220-250°C to find the minimum temperature for your specific filament that still gives good layer adhesion. Most PETG prints best at 230-235°C in terms of stringing control.
• Wipe and coast settings: In OrcaSlicer, enable "Wipe while retracting" (set to nozzle diameter) and "Coast before retraction" (0.2mm³). These reduce the pressure in the nozzle before a retraction move, minimizing the ooze string that forms between travel moves.
• Travel speed: Increase travel speed to 250-300 mm/s. Faster travel moves snap the filament string before it has time to stretch across the gap. Combined with Z-hop (0.4mm), this virtually eliminates stringing on most Voron printers.
• Filament drying: Wet PETG strings significantly more than dry PETG. Dry PETG at 65°C for 6-8 hours before printing if you notice excessive stringing. PETG absorbs moisture more readily than ABS — a spool left out for 48 hours in 50% humidity will print noticeably worse.
• Fan speed optimization: Higher fan speeds (40-50%) can reduce stringing by cooling the filament faster after extrusion. However, excessive fan speed reduces layer adhesion. Find the minimum fan speed that eliminates stringing — typically 25-35% for most PETG brands.

PETG Layer Adhesion

PETG naturally has excellent layer adhesion — often stronger than ABS in Z-axis strength tests. The key factors to maintain that strength:

• Hotend temperature is the primary driver: PETG layer adhesion improves significantly from 230°C to 250°C. At 230°C, layer bonding is adequate for most parts. At 250°C, the part approaches near-monolithic strength. For functional parts that need maximum Z-strength, print at 245-250°C and accept some stringing (clean up with a heat gun or deburring tool).
• Minimize cooling for strong parts: If strength is the priority, reduce part cooling fan to 10-20%. The slower cooling allows polymer chains to diffuse across layer boundaries more effectively. For tall, thin parts that need both strength and detail, use 30-40% fan with a 245°C hotend.
• Layer height considerations: PETG bonds best with a 0.2-0.24mm layer height (with a 0.4mm nozzle). Thinner layers (0.12mm) actually reduce Z-strength because each pass deposits less material, creating a higher proportion of layer boundaries. Thicker layers (0.28-0.32mm) improve strength but reduce surface quality.
• Annealing PETG: PETG can be annealed at 70-75°C for 1 hour to improve heat resistance and relieve internal stresses. Place the part in a kitchen oven (verify temperature accuracy with a separate thermometer) or use a filament dryer. Parts may warp or shrink 0.5-1% during annealing — test on non-critical parts first.

Slicer Profiles for PETG on Voron

Recommended PETG Brands

• Polymaker PolyLite PETG: The gold standard for PETG on Voron printers. Excellent dimensional accuracy, consistent diameter (±0.02mm), low stringing, and beautiful surface finish. Prints cleanly at 230-240°C. Available in a wide range of colors including translucent options that show off Voron LED lighting. Price: $22-30/kg. Highly recommended as the first PETG to try.
• Overture PETG: A reliable and affordable PETG that balances price and performance well. Slightly more prone to stringing than Polymaker, but excellent layer adhesion and impact strength. Good tolerance (±0.03mm). Prints at 230-245°C. A popular choice for functional parts and prototypes. Price: $18-24/kg.
• eSun PETG: One of the most widely available PETG brands. Consistent quality with good layer adhesion. Slightly lower viscosity than some PETGs, which means it flows well at 230°C but strings more at higher temperatures. eSun PETG is a good choice when you need a large quantity at a competitive price. Price: $16-22/kg.
• Prusament PETG: Premium PETG with exceptional quality control (±0.02mm). Made in Prusa's Czech facility. Extremely consistent from spool to spool. The surface finish is among the best of any PETG. Higher price point but zero quality issues. Price: $30-36/kg.
• Atomic Filament PETG: American-made PETG known for excellent color quality and low stringing. The "Dark Jade" and "Deep Blue" colors are particularly popular. Good layer adhesion at 235-245°C. Slightly higher printing temperature needed than other brands. Price: $28-35/kg.
• IIID Max PETG: A budget-friendly option that performs surprisingly well. Good adhesion, consistent diameter, and decent stringing control. Best value for large prints or when burning through spools quickly. Price: $14-19/kg.

Common PETG Problems and Fixes

• Blobs and zits on the surface: Caused by pressure buildup in the nozzle during retraction. Fix: Enable "Wipe before retract" and reduce retraction distance by 0.2mm. Also check that your pressure advance value is calibrated (run the Klipper pressure advance tuning tower).
• Poor overhang quality: PETG bridges and overhangs worse than PLA because it cools slowly. Fix: Increase part cooling fan to 50% for overhangs, reduce speed to 40-60 mm/s for areas with overhang angles >45°, and enable "Slow down for overhangs" in the slicer.
• Layer separation or delamination: PETG layers can separate if printed too cool or with too much fan. Fix: Increase hotend temperature by 5-10°C, reduce fan speed to 20%, and verify you're not exceeding the volumetric flow rate (PETG maxes out around 20-25 mm³/s on a standard Voron hotend).
• Filament grinding in extruder: PETG is softer than PLA and can be chewed up by high-tension extruders like the Clockwork 2. Fix: Reduce extruder tension slightly, increase retraction speed (but keep distance low), and ensure your PTFE tube has minimal friction. Also check for heat creep — PETG softens in the heatbreak if the hotend fan is inadequate.
• Bed adhesion failure: PETG lifts from the bed if there are drafts or uneven temperatures. Fix: Use a brim (5mm width, 0mm gap) for parts with small contact area. Ensure the bed is clean (isopropyl alcohol wipe between every print). Increase bed temp to 80°C for stubborn materials.
• Cloudy or hazy translucent parts: PETG becomes cloudy when printed too cool or with too much cooling. Fix: Print translucent PETG at 245-250°C with 15-20% fan speed. Slower printing produces clearer parts. A 0.6mm nozzle at 0.3mm layer height gives the clearest results.

Printing PETG Without an Enclosure

One of the biggest advantages of PETG on a Voron is that it prints beautifully without an enclosure. However, there are some considerations:

• Drafts are still a problem: Even though PETG doesn't need a hot chamber, cold drafts (air conditioning, open windows) can cause localized cooling that leads to warping on large flat parts. If printing on an open Switchwire, position the printer away from vents and windows.
• PETG on enclosed Vorons: If you have a V2.4 or Trident with the enclosure closed, the chamber will naturally heat to 35-45°C from the bed alone. This is fine for PETG — it won't warp, but the warmer chamber may slightly increase stringing. Leave the top hat panel cracked open 5-10mm to allow some heat and moisture to escape.
• Fumes: PETG produces less fumes than ABS, but the odor (sweet, slightly chemical) is not pleasant. Printing in a well-ventilated room is recommended. The Nevermore filter is not necessary for PETG but helps if you're sensitive to odors.
• PEI sheet temperature: If your Voron uses a magnetic PEI bed, ensure the magnets are rated for 80°C. Standard ferrite magnets lose holding strength above 80°C. Most Voron kits use 100°C-rated magnets, but verify if you're running bed temperatures at the upper end of the PETG range.

Advanced: PETG-CF and Filled PETG

Carbon fiber filled PETG (PETG-CF) combines the toughness of PETG with the rigidity and dimensional stability of carbon fiber. It prints at 245-260°C with a hardened nozzle (0.4-0.6mm). PETG-CF has significantly less warping than standard PETG and produces matte, textured parts. The carbon fiber also makes the material stiffer and more dimensionally stable for functional parts. Recommended brands: Atomic Filament PETG-CF, Polymaker PETG-CF. Note that PETG-CF is abrasive and will wear brass nozzles quickly — use hardened steel or ruby nozzles.