The importance of drying filament even if it is straight from the factory
Brand new roll of Prusament PC-CF, made on Sep 27, 2025 and still in the vacuum sealed bag with desiccant. Seal on the bag was intact when I opened it. Ran a large print and the surface quality was poor with lots of zits and other artifacts that indicated wet filament. Popped it in the dryer at 80C for 6hrs and there is a night and day different in print quality.
Moral of the story is even factory sealed filament can be wet. Invest in a dryer. Either a food dehydrator or a dedicated filament dryer. Don't rely on factory sealed filament arriving in printable condition unless it was packed in a desert and you live in a desert.
Anyway, I always now as a rule dry the filament before using it for the first time and store it in a sealed dry box with desiccant. If I see the hydrometer go past 25% I pop it in the dryer before use.
RE:
More on this to illustrate the point. First example is Siraya Tech TPU 64D immediately after it arrived and was removed from a vacuum sealed bag with seal intact (left) and after drying for 6 hrs (right). Second example is Prusa PC-CF with the same conditions, removed from factory sealed bag and after drying for 6 hrs.
