VISUAL SYMPTOM LIBRARY
See the symptom before you name the cause.
These are educational illustrations designed to help you recognize patterns. They are not laboratory photographs and they should never be used as proof of a diagnosis by themselves.
FilamentFix rule: a symptom is evidence, not a verdict. Match the visual clue with sound, storage history, material and a controlled next test.
Dry vs moisture-affected extrusion
Look for repeated roughness, bubbles and instability rather than one isolated imperfection. Run the moisture diagnostic →
Stringing with moisture clues vs tuning-related stringing
Stringing by itself is weak evidence of moisture. Popping, bubbles and exposure history make the moisture hypothesis stronger. Moisture vs retraction →
What moisture can do inside the hotend
Repeated popping plus bubbles or a visibly disturbed purge strand is more useful than stringing alone. Diagnose bubbles →
Under-extrusion vs partial clog
Missing material describes the result; a partial clog is only one possible cause. Under-extrusion diagnostic →
Layer separation vs missing layers
A clean crack often points toward bonding/cooling/warping; sparse missing material points toward extrusion problems. Layer adhesion diagnostic →
First layer too high, correct or too low
Do not compensate for poor adhesion by endlessly lowering Z. First-layer diagnostic →