How to Prevent PETG Warping on the Print Bed

Question: How do I stop PETG from warping off the bed?

Answer: To prevent PETG from warping, start by ensuring your print bed is clean and free of grease or dust—use isopropyl alcohol to wipe it down. Set the bed temperature between 70°C and 80°C to help the first layer stick well. Use a suitable build surface like PEI sheets, glass with a glue stick, or specialised PETG-friendly tape. Apply a thin layer of glue stick or hairspray if needed for extra adhesion. Adjust your first layer height to be slightly lower than usual, so the filament is squished onto the bed, improving grip. Print the first layer slower, around 20-30 mm/s, to allow better adhesion. Avoid drafts or sudden temperature changes around the printer, as these can cause warping. If your printer has an enclosure, use it to maintain a stable temperature. Finally, ensure your print cooling fan is off or at a low speed during the first few layers to prevent rapid cooling which leads to warping. Following these steps will significantly reduce PETG warping issues.