The stringing and blobbing that shows up every summer on my Ender 3 isn't a slicer problem, a temperature problem, or a retraction problem. It is a humidity problem.
I haven't fixed it yet. This is not a guide — it's an attempt to stop misdiagnosing the same failure mode for the fifth season in a row.
The thing I kept doing wrong
Every time prints started degrading, I went straight into slicer tuning. Retraction up. Temperature down. Slight tweaks that sometimes appeared to help, but never consistently. That pattern was the trap.
The real variable wasn't in the slicer. It was in the spool. Specifically: how much moisture the filament had absorbed since it was last sealed. That changes continuously with ambient humidity, especially across seasons.
Once I correlated failures with weather patterns — summer humidity spikes vs. winter stability — the slicer-based explanation stopped holding together.
What I think the actual fix looks like
This is not implemented yet. It is an architecture problem more than a solution.
1. Drying before printing
A food dehydrator is the most practical candidate. It is cheap, widely available, and designed to hold sustained low temperatures for long periods. That matches the requirement profile for filament drying.
The constraint is temperature control. PLA, PETG, and other materials have narrow thermal margins. Excess heat introduces deformation risk while trying to remove moisture. This is a parameter space problem that still needs validation.
2. Storage after drying
Drying alone is insufficient if the spool immediately returns to a humid environment. Storage needs to be sealed, with desiccant, and ideally monitored.
A basic hygrometer inside a sealed container is the simplest feedback mechanism. Without measurement, the system is guesswork.
3. Printing from a controlled environment
The last layer is delivery. Even dry filament can reabsorb moisture during long prints if exposed to ambient air.
A PTFE passthrough from a sealed dry box to the extruder is the logical extension. Not necessarily required — but potentially necessary in high-humidity conditions.
What I'm still not sure about
There are still unresolved variables in this system.
How long does a wet spool actually need in a dehydrator before it reaches stable conditions? Most available guidance is inconsistent and highly dependent on filament type and saturation level.
Whether consumer dehydrators are stable enough for repeatable filament drying, or whether dedicated filament dryers are required for consistency.
Whether a sealed storage + drying workflow eliminates the need for active dry-box printing entirely, or if that final step is still necessary in practice.
Where this leaves me
The humidity diagnosis is not fully proven, but it is strongly supported by seasonal consistency. That alone is progress compared to repeatedly adjusting slicer parameters for a system-level storage problem.
The next step is building the drying and storage pipeline and measuring outcomes rather than tuning assumptions.