When loading material into an FDM printer, why is it best to let a little of the material run out of the nozzle?

Allowing a small amount of material to flow out of the nozzle when loading an FDM (Fused Deposition Modeling) printer ensures that the filament is correctly primed and flowing as intended. This practice helps eliminate any air bubbles or blockages that may exist within the extrusion path.

When the material flows freely from the nozzle, it indicates that the nozzle is clear and that the temperature is suitable for melting the filament. This step is essential for ensuring that the first layers of a print adhere correctly to the build platform without interruptions or inconsistencies in extrusion, which could lead to poor print quality or even failed prints.

Checking the flow helps confirm that the printer is ready to start the actual printing process without issues related to material feed.