Black Specks and Color Streaks in Prints

Streaks of an old color

Leftover colorant, often from dark reds or blues, works loose during a later print. Purge with 3D Clean until no color shows in the output before switching to a light color.

Black specks

Black specks are carbonized plastic. Material that sat in the hotend too long, often in pits worn by abrasive filaments, breaks down, shrinks, and breaks free. These specks are stubborn and can take a while to come out.

• Purge with 3D Clean at the temperature of the hottest recent material.
• Keep going until no black specks come out at all, not just fewer.
• If specks keep returning after a thorough purge, the hotend may be worn inside. Consider replacing the nozzle.

See Purging filled filaments.