Filament Maker:
rPET Print Settings
A complete guide on the perfect print settings for recycled PET Filament made using or Filament Maker
Recycled PET (rPET) filament is a fantastic material for sustainable 3D printing, offering strong, reliable prints while keeping plastic waste out of landfills. However, printing with rPET requires fine-tuned settings to achieve the best results—especially when using filament produced with our Filament Maker.
This guide provides optimized print settings for PRUSA MK4s, PRUSA MK3s, BambuLab X1C, BambuLab P1S, and Creality Ender 3. Since rPET behaves differently from standard PETG or PLA, dialing in the right extruder temperature, bed temperature, fan speed, and retraction settings is essential for strong adhesion, smooth layers, and minimal stringing.
Below, you'll find our recommended settings based on real-world testing, ensuring consistent performance across different printers. Plus, we've included downloadable slicer profiles to help you get started with minimal setup.
Let's dive into the ideal parameters for rPET printing! 🚀♻️
Introduction
Getting Started
You will need:
1.75mm Filament made using our FIlament Maker
A FDM Printer with high temp hotend and heated chamber such as the Bambu Lab X1C Printer.
Optional Extras:
Filament Drier
Drying you filament before printing with it is HIGHLY recommended. Skipping this step can cause stringing and poor layer adhesion.
FAQs
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Recycled PET is a versatile material, but it has some unique properties that affect what you can successfully print. While it offers good durability and resistance to moisture, it is not ideal for very thin or highly detailed parts that require strong layer bonding.
What works well:
✅ Functional parts – Brackets, tool holders, storage containers, and similar items that don’t rely on extreme thinness.
✅ Structural components – PET has good stiffness, so larger, solid parts perform well.
✅ Water-resistant objects – PET’s low moisture absorption makes it ideal for outdoor items, bottle adapters, and utility clips.
✅ Experimentation & prototyping – PET is a great material for testing designs that don’t need extreme strength across the layer lines.What to avoid:
❌ Thin-walled or intricate models – PET does not bond as strongly between layers as some other materials (e.g., ABS or nylon), making slim parts prone to splitting under stress.
❌ High-detail miniatures – Fine details may not print well, and small unsupported sections can be fragile.
❌ Load-bearing parts under bending force – PET is strong when printed flat, but parts that rely on strength across the layer lines can be weak.Tips for Success:
Increase infill – A higher infill percentage can improve part strength.
Use rounded, thicker designs – Avoid sharp corners and extremely thin features to reduce weak points.
Print orientation matters – Try to orient parts so that forces act along the printed layers, not across them.
The best way to learn what works is to experiment! PET is a fantastic material when used correctly, so test different designs and print settings to find what works best for your needs.
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If you’re experiencing issues with print quality or filament not extruding properly, follow this checklist to troubleshoot:
Correct strip size: Ensure the PET bottle strips are the right width for your bottle thickness. As a general guide:
10mm strip for 0.1mm bottle thickness
9mm strip for 0.2mm bottle thickness
8mm strip for 0.3mm bottle thickness
Filament shape: The extruded filament should form a consistent tube shape, not a “C” shape. Adjusting strip width or extrusion settings can help correct this.
Filament diameter: Measure the filament near the spool (after cooling) to ensure it is within 1.65mm–1.85mm (ideally as close to 1.75mm as possible). Fine-tuning the strip size will improve consistency.
Print settings: Default PETG settings may not work well with recycled PET. Ensure you're using our recommended print settings for optimal results.
Cleanliness: Any residue from bottle labels or adhesives can cause blockages and poor extrusion. Make sure bottles are fully cleaned before processing.
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This is usually caused by moisture absorption, as PET is highly hygroscopic (absorbs water from the air). To ensure high-quality prints:
Dry your filament before printing: We recommend using a dehydrator or filament dryer.
Drying time and temperature: Minimum of 2 hours at 65°C, though longer drying times may be required depending on humidity levels and filament quantity.
Proper storage: Keep filament in an airtight container with desiccant when not in use to prevent reabsorption of moisture.
Understanding rPET Print Settings
When printing with recycled PET (rPET) filament, dialing in the correct print settings is crucial for achieving strong, high-quality prints. The recommended settings above were carefully tested using our Filament Maker and various 3D printers. However, different models—and even slight variations in filament—can require small adjustments to optimize print quality.
Key Settings & Adjustments
Extruder Temperature: rPET requires higher temperatures than PLA or standard PETG. We found that 255–265°C provides strong layer adhesion while minimizing oozing and stringing. If prints appear brittle, slightly increasing the temperature may help, while reducing it can help control stringing.
Bed Temperature: Keeping the bed at 80°C improves first-layer adhesion and reduces warping. If you're experiencing adhesion issues, consider using a textured PEI sheet or an adhesive like a glue stick.
Retraction Settings: Since rPET can be prone to stringing, retraction distance and speed are key. We've tested 1mm at 20-30mm/s, but this may vary depending on your printer. If you notice excessive stringing, increasing retraction slightly may help.
Flow Rate (Extrusion Multiplier): rPET filament can vary in density depending on how it was produced. We've found a 130% flow rate ensures proper extrusion and reduces under-extrusion issues. If prints look too thick or over-extruded, reducing the flow rate in your slicer can fine-tune this.
Print Speed & Layer Height: A moderate speed of 40mm/s balances detail and strength. Slower speeds may improve surface finish, while faster speeds can be used if your printer has good cooling and rigidity. A 0.15mm layer height ensures good detail while maintaining strong layer bonding.
Fine-Tuning for Your Printer
These settings were tested across several common printers, but other models will absolutely work—they may just require small adjustments. If you're using a different machine, start with these settings and tweak based on your print results. Many slicers, including PrusaSlicer, Bambu Studio, and Cura, allow easy modifications to temperature, flow rate, and retraction settings.
Lastly, the final print quality relies heavily on creating consistent, high-quality filament in the first place. Following our Filament Maker instructions precisely ensures your rPET filament is smooth, properly extruded, and free from inconsistencies—making printing much easier and more reliable.
Setting | PRUSA MK4s | PRUSA MK3s | BambuLab X1C | BambuLab P1S | Creality Ender 3 |
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Nozzle | 0.4mm | 0.4mm | 0.4mm | 0.4mm | 0.4mm |
Extruder Temperature | 255℃ | 255℃ | 265℃ | 265℃ | 260℃ |
Bed Temperature | 80℃ | 80℃ | 80℃ | 80℃ | 80℃ |
Fan Speed | 40% | 40% | 40% | 40% | 40% |
First Layer Height | 0.1mm | 0.1mm | 0.1mm | 0.1mm | 0.1mm |
Layer Height | 0.15mm | 0.15mm | 0.15mm | 0.15mm | 0.15mm |
Extrusion Multiplier (Flow) | 130% | 130% | 130% | 130% | 130% |
Max Volumetric Speed | 6mm/s | 6mm/s | 6mm/s | 6mm/s | 6mm/s |
Print Speed | 40mm/s | 40mm/s | 40mm/s | 40mm/s | 40mm/s |
Retraction Distance | 1mm | 0.8mm | 0.8mm | 0.8mm | 1mm |
Retraction Speed | 30mm/s | 20mm/s | 30mm/s | 30mm/s | 20mm/s |
Slicer Profiles
We understand that copying these settings into your slicer can be tedious. We have done the hard work for you. Here are some Slicer Profiles to help you get started.
Using PrusaSlicer
Using PrusaSlicer
Using Bambu Studio
Using Bambu Studio
Using UltiMaker Cura
Using OrcaSlicer