Filament quality does not end at the production line; the spool has to be protected for the whole time it takes to reach you. Vacuum packaging and desiccant protect exactly that stretch of time.
Why moisture matters this much
Left in the open at 50% relative humidity, PLA takes on a measurable amount of water within days. That water flashes to steam in the nozzle and leaves bubbles on the surface and weakness in the layer. An opened spool that has sat in storage for months needs drying before it prints well.
What is in the packaging
- Vacuum-sealed barrier bag: stops moisture ingress
- Silica gel: absorbs whatever moisture is left inside
- Batch label: production date and the diameter tolerance measured for that batch
Why the tolerance is printed
1.75 mm ±0.02 mm is what makes the amount of material the extruder pushes each second predictable. As tolerance widens the flow changes, and with identical settings you get under-extrusion in one area and over-extrusion in another.
What you should do
Open the packaging right before printing, and keep the spool in a box with silica gel afterwards. If it has been open a long time, dry it before you print.
