By Ferretpass with huge help from 3d Print General and CTRL+Pew.

A special thanks to Polymaker and Greengate 3d for providing the materials I used in this guide.

• PETG has more heat resistance and UV resistance to PLA. For example, if you leave a PLA print in a hot car the prints will tend to warp and melt. I left PETG prints in my car for around 2 weeks or so and they did not melt or deform due to heat. (I don’t live in TX or on the surface of the sun, YMMV)
• PETG does not have the same stiffness as PLA but PETG materials tend to bend; it does not really shatter under stress like PLA does.
• Both materials print very similar to each other and printability is great with both materials.
• PETG is not as good as PLA for overhangs and bridging so expect to use more support material with PETG.

What will you need to print these materials? Thankfully not much you will need just the filament and glue stick (: 

• If you want to print on or have a glass bed. Glue stick > https://amzn.to/3Auk96y
• Greengate3d  > https://amzn.to/3BtUX1j or https://greengate3d.com/?ref=gDtZD0Wf645eY or coupon ‘ctrlpew391’
• Polymaker Polylite > https://amzn.to/3lpAi9e
• Polymaker Polymax > https://amzn.to/3oLL8YY

Recommended upgrades these are not essential but they are nice to have:

• A Glass bed for Ender 3 sized printers > https://amzn.to/3mvhzIA | Alternatively a magnetic PEI coated print bed > https://amzn.to/2YxF6QC
• A metal extruder I’ve been using this one and its worked flawlessly plus it comes with upgraded bed springs and blue PTFE tubing> https://amzn.to/300EUdu
• A food dehydrator. PETG absorbs moisture quite readily > https://amzn.to/3FtLqK4 This one will work any circular one with an adjustable temp should do fine. You will have to cut out the grate between the levels to get the spool to fit.

Notes

• If you are printing on a glass bed use a glue stick. PETG will bond to bare glass and it will shatter your build plate.
• Temp settings can range from 230c to 240c and hotter. If you have an all metal hotend, I personally recommend 240c for these PETG’s.
• I recommend not using a cooling fan or a very low cooling fan for maximum strength.
• It should go without saying, print in a well ventilated area. Also, I am not responsible for your bodily harm or property damage.
• Filament may need to be dried. PETG adsorbs more moisture than PLA or ABS filament. I recommend getting a food dehydrator, building a dry box, or getting a filament dryer. CNC Kitchen made a great video on making a dry box from scratch. https://youtu.be/WEFtUKGAd7k I would also recommend drying your filament for 24 hours.
  •  If you want to get a dryer, https://www.amazon.com/dp/B08C9RZPMN/ref=cm_sw_r_apan_glt_fabc_XQ8VA4775EPXDBAZ6Q3X?_encoding=UTF8&psc=1 this is the one I use.
  • Make sure you use the recommended settings for the material with your dryer. I think I used 55c for 24 hours on this sunlu one for PETG.
• Layer heights, I recommend whatever works for you with PLA prints. I used a variety for this guide. I used 0.16 for structural parts and 0.28 if I wanted to print fast and less detailed models. I used a 0.4mm nozzle for all the prints in this guide. I didn’t try any other nozzle sizes but I am sure other sizes would work fine. 
• I personally use Cura as my 3D printing slicer. For some better prints I recommend using Chep profiles and using these settings he explains in this video. https://youtu.be/jkAqTWmVRVA
• I also recommend watching 3D Print General’s video on this subject. https://youtu.be/Na6PXrIKBXk

Learning new processes can be stressful. Remember to take breaks and don’t get frustrated if your prints don’t succeed the first or fifth time.

https://twitter.com/ferretpass/status/1443594055108153346?s=19

For what materials you should use I would say Greengate3D has a PETG very similar to the performance of PLA/PLA+ if you need a very rigid part I would use Greengate3D PETG. If you need a part with high impact resistance and flexibility before breaking I would use  Polymaker PolyMax PETG.If you followed those steps correctly you shouldn’t disturb the particle accelerator.