You paint supports onto a model in Bambu Studio, slice, and nothing shows up. Start with Enable support: with that box unticked, painting generates nothing, and Bambu's stock presets ship with it unticked. Then check which button you used. Left-click strokes show in blue and enforce support; right-click strokes show in red and block it. With support enabled, a left-click stroke on an overhanging face gets support regardless of the angle threshold, on auto and manual types alike; auto types simply add their own detected overhangs on top. If the cavity still slices empty after that, drop a support enforcer cube into it.
Bambu Studio has three ways to add support, and it is not obvious which one applies when. If you have not got the basic workflow down yet, start with the first-print guide.
One defect that gets blamed on support but has nothing to do with it: the infill pattern showing on the top surface.
The three methods
| Method | What it does | When |
|---|---|---|
| Automatic | Places support everywhere past the angle threshold | Most work |
| Support painting | Marks specific faces | When automatic overdoes it |
| Support enforcer | Forces support inside a volume | When painting does nothing |
Automatic
You tick Enable support and leave Support/object XY distance and Threshold angle at defaults. The threshold defaults to 30°: an overhang whose angle to the horizontal is below 30 degrees gets support, and raising the value adds more support.
The problem is automatic support putting material where it is not wanted. On a complex model it fills every cavity and makes removal much harder.
Support painting
With Support painting you brush over the model. Left-click strokes enforce support and show in blue; right-click strokes block it and show in red.
All painting needs is Enable support turned on; any Type works. On an auto type your strokes are added to the automatic support, and on a manual type they are the only support. There is no hybrid type anymore: since version 1.4.1 hybrid is a style, so you pick tree(auto) as Type and Tree Hybrid as Style, and older projects saved with hybrid(auto) open as tree(auto). With support switched off, painting does nothing at all.
Support enforcer
The method for when painting is not enough, and the real fix when a painted cavity still slices empty.
- Finish painting and exit painting mode.
- Right-click the model → Add support enforcer → Cube (or another shape).
- Move the blue cube into the cavity you want supported.
- Scale the cube slightly smaller than the cavity.
- Slice.
The enforcer forces the slicer to place support inside that volume, whatever the angle threshold says. If the cube is larger than the cavity the support spills outside, so you start small and grow it if needed.
The opposite exists too: Add support blocker keeps support out of a volume. Why a blocker sometimes seems to do nothing, and the other ways to strip unwanted support, are in the support blocker guide.
Settings
| Setting | What it is for |
|---|---|
| Support type | Normal or Tree, each in auto or manual |
| Threshold angle | Overhangs flatter than this angle (from horizontal) get support |
| Top Z distance | Gap between support and part: removal ease |
| Base pattern | The support infill pattern |
| Support/object XY distance | Side clearance |
Top Z distance makes the biggest difference. Near zero and the support welds to the part and will not come off; too large and the support does nothing and the surface droops. Bambu's common process profile defaults it to 0.2 mm; raise it if the support will not come off, lower it if the surface droops.
Tree support works with fewer contact points on organic models and removes more easily. Under wide flat surfaces, normal support is more reliable.
Avoiding support altogether
The best support is the one you never place, since it marks the surface wherever you pull it off. Ways to fix an overhang without support are in the overhang article.
- Rotate the part. Most models will print unsupported at some orientation, so try a few in Preview. The rotation tools are in rotating, scaling and mirroring.
- Split the model. Printing two pieces and gluing them beats printing one piece with support.
- The 45° rule. Overhangs up to 45 degrees from vertical print unsupported. If the design is yours, do not exceed it.
- Bridges print unsupported. A horizontal gap anchored at both ends needs no support unless the span is long.
If you came here to switch support on because the slicer threw a floating regions warning, check the cause first. Of the two causes behind the floating regions warning, one is fixed in the model rather than with support.
