Vase mode strips a print down to one wall. Instead of building solid infill and stacking multiple perimeters layer by layer, the slicer prints a single outline that spirals up continuously from the base to the top, so the finished object comes out hollow, light, and fast to print. It is one of the few slicer settings that changes the shape of the toolpath itself, not just a parameter inside a normal print, which is part of why it behaves so differently from everything else in the software.
The feature goes by different names depending on the slicer. PrusaSlicer calls it Spiral vase. Cura calls it Spiralize outer contour. OrcaSlicer and Bambu Studio call it Spiral vase, tucked under Special mode. All three do roughly the same thing: take a shape that can be described as one closed outline per layer, and turn it into a single unbroken path that rises in a smooth spiral instead of stepping up in flat steps. Get it right and you end up with lampshades, planters, and decorative containers that come off the plate looking almost polished. Get it wrong and the cause is almost always the same: the model was never a single closed shape to begin with.
How spiral vase mode actually works
In a normal print, each layer is a closed loop, or several. The nozzle finishes the loop, lifts slightly if z hop is on, and starts the next layer at a new Z height. Spiral vase mode removes that layer change for the walls entirely. After a set number of solid bottom layers, the printer keeps extruding while the Z axis rises continuously along the X and Y path, so there is never a moment where the nozzle stops, retracts, and restarts a loop. That continuous motion is what erases the vertical seam a normal print gets from starting and stopping perimeters at the same XY point on every layer.
Because there is no restart, retraction and z hop are effectively switched off for the length of the spiral. There is nothing to retract for, since the nozzle never leaves the surface, and no reason to hop, since it never crosses open space. Wall count locks to one in true vase mode. Some slicers will let you set more than one, but then the path is no longer continuous and you lose the whole point of the setting. Infill drops to zero and top layers get disabled, since there is no flat surface left to cap. Spiral vase mode never touches the base, though. Those first few layers print solid and flat exactly like a normal print, so the object has something to stand on before the wall takes over.
Spiral vase in PrusaSlicer
In PrusaSlicer, the setting lives in Print Settings under Advanced, or under Vertical shells in the simple view, as a single checkbox labeled Spiral vase. Turning it on sets perimeters to one, infill to zero, disables top solid layers, disables supports, and turns off ensure vertical shell thickness automatically, since none of those settings do anything useful once a single wall is doing all the work. You can still choose how many bottom solid layers print before the spiral starts, and you can raise the external perimeter extrusion width in the Advanced settings, say from 0.45 mm to 0.6 mm, to get a thicker and sturdier wall without adding a second perimeter. PrusaSlicer also expects the model to be modeled as a true solid rather than a hollow shell. If the object already has wall thickness built into the mesh, the slicer will try to trace both an inner and an outer surface and the spiral will not come out right. Model the outside shape only and let PrusaSlicer’s own wall thickness settings handle the rest.
Spiralize outer contour in Cura
Cura’s version sits under Special modes as Spiralize outer contour. Enable it and Cura prints the bottom layers of the model as a solid base first, the same way it would in a normal print, then switches to tracing a single wall in a continuous spiral for the rest of the height. Because Cura is generating one unbroken path instead of stacking flat layers, settings that only make sense layer by layer, such as top pattern or infill density, simply stop applying once the spiral starts. Worth knowing before you rely on it: several Cura versions have had reported quirks where bottom layer settings do not fully carry through once spiralizing kicks in, so a quick test print is worth more than assuming the base will look exactly like a non-vase version of the same model.
Spiral vase in OrcaSlicer and Bambu Studio
OrcaSlicer and Bambu Studio group this under Others in the print settings, inside a section called Special mode, where Spiral vase is a checkbox next to a second option called Smooth spiral. Turning on Spiral vase drops wall loops to one, sparse infill to zero, and disables the top shell automatically, much like PrusaSlicer’s behavior. Smooth spiral goes further: instead of smoothing only the Z motion, it also smooths the X and Y path, so seams disappear even on curved or tapered walls where a plain spiral would still show a faint line. Both slicers also expose separate starting and finishing flow ratio settings for the spiral, meant to prevent under extrusion right at the transition out of the solid base and again at the very top, along with a max XY smoothing value that limits how far the path can shift for the sake of a clean line. Push that value too high and it will round off sharp features you actually wanted to keep.
What you give up for one wall
A single wall with no infill has no structural backup behind it. Drop it or squeeze it and it will crease or crack where a normal print with even 15 percent infill would just flex back into shape. It is not watertight by default either. A 0.4 mm or 0.6 mm wall can still show pinholes at layer transitions or thin spots on a tight curve, so anything meant to hold liquid needs a thicker wall and an actual test fill before you trust it with water. There is also a geometric limit that has nothing to do with strength: the model has to be a single, closed, non branching outline at every height. Something with a hole through it cannot be spiral vased. Neither can a shape with two separate loops on the same layer, or a handle that splits off from the main body, because the slicer has no way to keep the path continuous once there is more than one loop to trace at a given height.
Where it helps and where it does not
Vase mode is at its best on actual vases, lampshades, planters, pen holders, and decorative single-wall containers where looks matter more than load. It also prints fast, since there is no infill to lay down and no top layers to fill in. It is the wrong setting anywhere strength matters. A flat top surface, a hole, a handle, anything that gets dropped, sat on, or clamped down, all of that pushes past what a single wall can do. If a part needs to look hollow but still carry some real strength, a normal wall thickness setting with a modest wall count, or adaptive layer height to keep the surface clean without going full vase, will usually get closer to what you actually need.
Getting a clean result
Most vase mode failures trace back to the model rather than the slicer. If the walls flare out or taper in faster than the wall width can bridge between one layer and the next, the transition zone ends up with gaps instead of a clean surface. Give the base a few extra bottom layers if the shape widens quickly right after the solid section, and keep the initial layer height reasonable rather than shaving it down for speed, the same logic that applies to layer height in general. Motion tuning matters more here than in normal printing, too. Because the nozzle never stops, any jerk, acceleration, or input shaping mismatch on the printer shows up as a visible wobble running the full height of the print, instead of being hidden inside one layer’s worth of movement. If a printer already handles corners cleanly in regular prints, spiral vase mode will usually look right on the first try. If it does not, that is worth fixing first, because vase mode has nowhere left to hide it.