Order of walls
The order in which the wall loops of each layer are printed: inside to outside, outside to inside, or inner-outer-inner. It changes how parts that stick out turn out, how the seam looks, and how accurate the dimensions are.
How it works
“Inner → outer” (the default): the inner walls first and the outer wall last. When the outer wall is printed, it already has a wall next to it to lean on. That matters on overhangs (parts that stick out with nothing underneath): the line hanging in the air grabs onto the inner wall and doesn't droop.
“Outer → inner”: the outer wall goes first and cools before the inner walls are printed against it. That way the inner walls don't push on it or deform it, and the outside dimensions come out more accurate. But the seam shows more and overhangs come out worse, because the outer wall is printed with nothing next to it.
“Inner → outer → inner”: first all the inner walls except one, then the outer wall, and finally the inner wall that sits right against it. The outer wall is printed without freshly laid walls squeezing it, and the others have already cooled: the surface comes out cleaner. On overhangs it behaves like “Outer → inner”.
When to change it
- A figurine with outstretched arms or the flared rim of a cup: “Inner → outer”.
- A box with a snap-on lid, where the outside size has to be exact and the surface shouldn't show marks: “Inner → outer → inner”, with 3 or more walls.
- A part that has to fit precisely on the outside and has nothing sticking out: “Outer → inner”.
Typical values
| Value | What for |
|---|---|
| Inner → outer | Default; best for overhangsdefault |
| Outer → inner | Accurate dimensions; worse seam and overhangs |
| Inner → outer → inner | Cleaner surface with 3 or more walls |
Watch out for
- “Inner → outer → inner” needs at least 3 walls to make sense; with 2 it's the same as “Outer → inner”.
- If the part has overhangs and you pick an order that prints the outer wall first, turn on supports or accept drooping edges.
Goes well with
What Bambu Studio saysits help card, quoted
What Bambu Studio says
Print sequence of inner wall and outer wall.
Bambu Studio tooltip for this setting · AGPL-3.0
Read more at the official source
In your profile0.20mm Standard @BBL A1 · inner/outer
In Bambu Studio, the profile 0.20mm Standard @BBL A1 sets it toinner/outer
In other slicers
- Orca Slicer
- Walls printing orderQuality › Walls and surfaces
- PrusaSlicer
- External perimeters firstLayers and perimeters › AdvancedIt's a checkbox: on means outer/inner; there's no inner/outer/inner.
- Cura
- Wall OrderingWallsOnly inside-out or outside-in; there's no inner/outer/inner.
Names taken from each program's code (Orca Slicer 2.4.2, PrusaSlicer 2.9.6, Cura 5.13.0). Credits