1-kg Dynamism PETG 2.85mm 3D Printer Filament (Blue, Gray or Red) Expired

I'm no long-time expert with years and years under my belt (I've only been into 3D printing for 18 months at this point, but have printed enough so that my printer has over 138.5 days of print time on it--an average of over 6 hours/day, every day, since I got the printer), In terms of my criteria, the main points to determine how good a filament is would be:
1. First layer adhesion
2. How well the filament handles overhangs/unsupported diagonal angles

On first layer adhesion--
The best filament "just sticks" and gives nice, smooth first layers.
Sometimes, it becomes necessary to add glue stick or something similar to get filament to stick, particularly if you're printing something with a bit of a complicated first layer with lots of holes, etc., in it.
Terrible filament will just not stick to the bed no matter what you do (increasing temps, adding glue, slowing the print speed, etc.). Of the filaments I've tried, there is only ONE line of filament that I've put into this category, and that is the matte finish PLA from eSun (their regular PLA is just fine, though). My printer (Ender 3 V2) handles many other brands of matte PLA without issue.

On testing overhangs--
My model of choice for this purpose is the "Stacktocat" - a remix of the "calibration cat" with modified feet so you can print lots of them and stack them to save shelf/table space (https://www.printables.com/model/...ation-cat)
In addition to a temperature tower (you'd be surprised to see how wildly different each spool of filament has a different "sweet spot" on nozzle temp), I will print one of these for just about every spool of filament I try to see how well it works, as this doesn't use much filament. The cat's tail is a great small 45 degree unsupported upward angle. The best filaments will handle this angle no problem, and the whole tail will be perfectly flat/square all around. Some other filaments will start to droop ever so slightly, so the bottom side of the tail will have a slightly lumpy texture to it instead of being nice and flat. This is where printing the exact same model from the exact gcode file allows you to attempt to isolate just the filament itself as being the difference in the resulting print quality (which, in reality, is not 100% possible, as the nozzle will always be in a different state of wear, etc.)

When I say I've tried a lot of different filament spools in my 18 months of printing, I'm talking:
PLA - 85+
PETG - 25+
ABS - 3
TPU - 2
PC - 1
I've even got more spools on hand that I haven't opened up yet.
The only reason I've had the opportunity to try so many different filaments is due to being in an Amazon program where I can get items in exchange for writing reviews on them (Amazon likes to claim this is "for free," but I actually end up paying income tax on the retail price of everything, similar to game show winnings). I've left reviews on so many filaments, one filament manufacturer has even appropriated my review images to use in their product advertising:
https://www.amazon.com/Filament-P...0C6ZDT7T4/
The last picture on that filament, where it says "Practice 3D printing," that's one of my Stacktocat pictures alongside a temperature tower.


Bonus free advice to any 3D printing beginners--if you have an unenclosed printer, I highly recommend picking up (or making) a printer enclosure of some sort. I got one about 9 months in, and the enclosure not only reduces warping of prints, it insulates the printer so the heaters don't have to run as much; for me, on PLA prints this amounts to the printer using 10-15 watts less than before getting the enclosure, so if you print a lot, an enclosure can start to save you money on your electric bill. (It's also pretty much required if you ever want to print ABS or PC).

I don't know if this was the case yesterday, but caution to anyone looking at it now, the remaining $10 filament appears to be 2.85 mm instead of the usual 1.75mm, just make sure people see that

It looks like the available colors are red, blue, grey, white, and black.

I'd buy some, but have enough of all those colors on hand already.

On the topic of trying new brands, though, I have tested A LOT of different brands, and there are very few I'd never buy again; some are better than others, but very few are downright terrible