I’ve had some issues with warping when printing with eSun PETG, which was surprising since I’ve never noticed any warping with PET before that. Since many people seem to be getting warp free prints with eSun PETG, I assumed it might be caused by PETG from the early production runs. So I purchased a new spool, and it does look quite a bit different (rougher texture to the filament). For a test object, I used a fin on my ski pulk as that was one of the prints I was having troubles with. The original was printed as a vase print, with a 1.5mm extrusion width. The retest was done at a 1/3rd scale, also as a vase print.
This is the eSun PETG, a new magenta spool, an older yellow spool, and an older magenta spool. They exhibit pretty much the same type of warping I was getting with the full sized prints. The warping eventually causes the part to pull off the print bed, which causes the entire print to shift.
When repeating the same test with other PETG filaments, the part printed the way it was supposed to. The parts in this picture are printed in 3D Solutech transparent blue PETG, Atomic Filament glow in the dark PETG, and MadeSolid transparent blue PET+.
This is the full sized part printed in eSun PETG, a solid 3mm thick vase print. I had to use a large brim to get it to print (the brim wasn’t strong enough to keep it from detaching, but it detached more gradually, spreading out the warping over a larger area). It’s held up pretty well so far, better than I expected being dragged though the snow, ice, rocks, and trees. In general the eSun PETG works well and looks good (and is one of the cheapest PETG options available), it just warps more than I’ve come to expect from PETG, at least for me.