Fixing stringing on printed bricks
Fine hairs between studs, or a fuzzy top face, spoil the click and the look. Damp filament is the usual cause, so start there.
What you will see
- Thin wisps of plastic between the studs or across gaps
- Rough, bubbly or fuzzy studs
- Crackling or popping from the nozzle while it prints (a sign of damp plastic)
What to try, in order
- Dry the filament. Damp plastic gives strings and rough studs, most of all in PETG. Dry the spool in a filament dryer, following the temperature on the spool, and print from a dry box if you can.
- PLA: turn the part-cooling fan up after the first layers.
- Slow the outer wall. Makers who print this kind of part report 25 to 60 mm/s for the outer wall; we have not tested every value ourselves.
- Lower the nozzle temperature a few degrees at a time; hotter plastic runs more.
- Check retraction is on in your slicer. Keep the preset at first and change it only if strings remain.
Change one thing at a time and test with one piece, not a whole plate.
Good to know
- PETG strings more than PLA. Compare by printing the same piece in both.
- Brims, drying and cooling matter more than clever slicer tricks for small studs.
- If the studs came out rough rather than stringy, see rough studs.
Where we give numbers, they come from our own tests on a Bambu P1S with a 0.4 mm nozzle plus advice from other makers, and other printers need small adjustments. Our print settings page has the full table. Printed bricks are not toys: small parts, a choking hazard, not for children under 3.