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 for best results. Set the bed temperature between 70-80°C to keep the first layers warm and adhered. Use a suitable build surface like a PEI sheet, glass with a glue stick, or blue painter’s tape to improve adhesion. Apply a thin, even layer of glue stick or hairspray if you’re printing on glass. Enable a brim or raft in your slicer settings to increase the surface area of the first layer, which helps hold the print down. Print the first layer slower (around 20-25 mm/s) and slightly lower the nozzle height to ensure good bed contact. Avoid drafts and sudden temperature changes by printing in an enclosed or semi-enclosed space. Finally, make sure your cooling fan is off or running at low speed during the first few layers to prevent premature cooling. These steps combined should significantly reduce warping with PETG.