PETG filament has increasingly become the new “big thing” in the 3D printing. In addition to the constantly expanding color selection, it has some of the best features of both PLA and ABS:
- It has a transition temperature point roughly equivalent to ABS, allowing it to handle higher ambient temperatures than PLA
- It sticks to bed treatments such as our 3D-EEZ or the Elmers / Water Glue mix like PLA
- PETG is far more elastic than PLA. Even thin pieces can endure quite a bit of flex without cracking or breakage
- Typically does not warp
- Requires no cooling on most prints, but if desired, can be mildly cooled- unlike ABS
Like many things, PETG is not without a few quirks and can be temperamental to print with. The most negative aspect of using this filament is its habit of blobbing around the tip of the nozzle, particularly when mildly over extruding. The blob can become dislodged and stick to the print, possibly causing the nozzle to skip if it hits the blob; or becoming firmly attached to the outside surface of the print, making a blemish where it has to be removed.
To manage this particular quirk, you must monitor and adjust the print while underway. Using the pause feature in Matter Control or S3D, simply move the nozzle up 30 or so millimeters and use needle nose pliers to grab the blob and remove it from the nozzle. Once removed, press resume to continue the print.
PETG also is a bit stringy. Increasing the retraction a bit and fine tuning the temperature can help reduce or eliminate stringiness.
Due to the high heat, excessive cooling can cause weak layer adhesion, and is not recommended. Small intricate prints require printing in multiples to allow each layer to cool sufficiently.
Like most filaments, batches and colors can vary. We have found that the glow-in-the-dark version of PETG has almost no blobbing. One of the better qualities of this type of filament, even with the extra pain of printing, would be that the final parts glue very well with household super glue. One of the first prints I made had several parts glued together. To test strength, I dropped the model from approximately 5 feet onto a hard surface multiple times, and the weld held. With PLA this would not have been possible. Support structures can be easily removed by breaking them off or using an exacto knife.