Fix holes and missing faces in your model

Visible gaps in the sliced preview — or walls that vanish mid-print — usually mean the mesh has holes: faces that simply aren't there. Small holes can slip through slicing silently and ruin a print hours in.

Why it happens

Holes appear when meshes get decimated too aggressively, when a download is corrupted, when faces are accidentally deleted in editing software, or when a scan didn't capture full coverage.

How to fix it (about 30 seconds)

1. Drop the file into the Ferdelance checker (free, no account) and look for the amber outlines — each one is an open hole.
2. Click Auto-Repair. The pipeline traces every boundary loop and caps it with clean triangles, retrying with stronger settings until the mesh closes.
3. Download the repaired file and re-slice. If a hole is genuinely too large to close automatically, the tool tells you honestly instead of pretending.

More fix guides

• How to fix non-manifold edges
• Your 3MF isn’t watertight — here’s the fix
• Repair a 3MF without losing your AMS colors
• Free STL repair that never uploads your file