What causes under-extrusion?

It’s usually a mix of settings (flow/retraction/speed), temperature, and mechanical factors. Start with calibration tools, then verify hardware basics.

How do I fix under-extrusion fast?

Apply the top fixes in order and re-test after each change. Use the linked PrintFix Pro tools to dial in flow, temperature, and motion settings.

Should I change multiple settings at once?

No — adjust one variable at a time so you can see what actually improved the print.

3D Print Defect Fix • Step-by-step

Fix Under-Extrusion

Thin or missing lines, weak walls, gaps between infill and perimeters.

Run Diagnose Open Tools Fix My Print Hub

Quick Fix Checklist

Identify the symptom and confirm it with a simple test.
Apply the top fixes below one at a time.
Use the linked tools to dial-in settings.
Re-test and lock the result into your slicer profile.

Top Fixes for Under-Extrusion

Calibrate flow/extrusion (EM/flow rate) before chasing smaller tweaks.
Verify temperature (too hot = strings/blobs, too cold = weak flow/adhesion).
Reduce speed/acceleration on detail-heavy parts; stabilize mechanics.
Improve cooling/bridging and travel behavior (retraction + wipe/coast where appropriate).
Check filament condition (wet filament causes inconsistent extrusion + surface artifacts).

Recommended PrintFix Pro Tools

Flow / Extrusion Calibration
Extrusion Multiplier
Bed Level Gap

Related Guides

Fix 3D Prints (Complete Guide)
3D Printing Calculators
Slicer Cheat Sheets