ASA on the Prusa MK4S
Yes, but it takes extra gear or care. The MK4 with a high-flow brass nozzle. Same open frame, faster prints.
ASA is tricky on the Prusa MK4S
No enclosure on this printerPrinter
The Prusa MK4S is open to the room, and ASA warps and cracks in open air. Small parts can survive; for anything bigger, add an enclosure (even a grow tent or a box over the printer helps).
Fumes: give it fresh airMaterial
ASA gives off unpleasant fumes while printing. Run it in a ventilated room you are not sitting in, or vent the printer outside.
Buying the CF version of ASA?
Carbon-fiber filament sands down the Prusa MK4S’s stock nozzle. Plain ASA is fine; for the CF variant, fit a hardened steel nozzle first (a cheap swap).
Safe starting ranges for ASA as a family, not gospel. Each spool below has its exact manufacturer numbers, the dated source, and one-click slicer settings on its page.
Top ASA picks for the Prusa MK4S
Editor-tested spools and Prusa's own line: start here.
Best first ASA to try: UV-stable, warp-resistant outdoors, and easier to print than many ASA brands.
More ASA spools
110 ASA filaments in the catalog, popular brands first. See the full ASA list.